Gross Bradley J.

SEC source: 0001447253-26-000003 · wk-form4_1778023975.xml · nonDerivative · entry 1

Gross Bradley J. · CIK 0001447253 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 8,789

F1 · kind: Reflects a repurchase of shares by Stagwell Inc. (the "Issuer") pursuant to a Share Repurchase Agreement, dated May 4, 2026.

F2 · ownership.nature: The Reporting Person is a managing director of Goldman Sachs & Co. ("Goldman Sachs"). Goldman Sachs is a subsidiary of The Goldman Sachs Group, Inc. ("GS Group"). GS Group is the direct owner of Bridge Street Opportunity Advisors, L.L.C., the general partner of each of StoneBridge 2017, L.P., which directly held 1,597,531 shares of Class A Common Stock of the Issuer reported as sold herein, and StoneBridge 2017 Offshore, L.P., which directly held 566,259 shares of Class A Common Stock of the Issuer reported as sold herein. Goldman Sachs beneficially owned directly and GS Group may be deemed to have beneficially owned indirectly 8,789 shares of Class A Common Stock of the Issuer. The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any.

SEC source: 0001447253-25-000008 · wk-form4_1764632816.xml · nonDerivative · entry 1

Gross Bradley J. · CIK 0001447253 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 2,293,238

F1 · kind: This transaction represents a donation of shares of the Issuer's Class A Common Stock to a charity.

F2 · ownership.nature: The Reporting Person is a managing director of Goldman, Sachs & Co. ("Goldman Sachs"). Goldman Sachs is a subsidiary of The Goldman Sachs Group, Inc. ("GS Group"). GS Group is the direct owner of Broad Street Principal Investments, L.L.C., which directly held the 5,341,715 shares of Class A Common Stock of the Issuer reported as donated herein, and Bridge Street Opportunity Advisors, L.L.C. is the general partner of each of StoneBridge 2017, L.P., which directly holds 1,597,531 shares of Class A Common Stock of the Issuer, and StoneBridge 2017 Offshore, L.P., which directly holds 566,259 shares of Class A Common Stock of the Issuer. Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 129,448 shares of Class A Common Stock of the Issuer. The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any.

SEC source: 0001447253-25-000006 · wk-form4_1757369031.xml · nonDerivative · entry 1

Gross Bradley J. · CIK 0001447253 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnotes

Disclosed balance after: 7,655,879

F1 · kind: This transaction represents a donation of shares of the Issuer's Class A Common Stock to a charity.

F2 · ownership.nature: The Reporting Person is a managing director of Goldman, Sachs & Co. ("Goldman Sachs"). Goldman Sachs is a subsidiary of The Goldman Sachs Group, Inc. ("GS Group"). GS Group is the direct owner of Broad Street Principal Investments, L.L.C., which directly holds 5,341,715 shares of Class A Common Stock of the Issuer, and Bridge Street Opportunity Advisors, L.L.C. is the general partner of each of StoneBridge 2017, L.P., which directly holds 1,597,531 shares of Class A Common Stock of the Issuer, and StoneBridge 2017 Offshore, L.P., which directly holds 566,259 shares of Class A Common Stock of the Issuer. Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 150,374 shares of Class A Common Stock of the Issuer. The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any.

SEC source: 0000950170-24-074527 · ownership.xml · nonDerivative · entry 1

Gross Bradley J. · CIK 0001447253 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 12,981,022

F1 · kind: Reflects a repurchase of shares by Stagwell Inc. (the "Issuer") pursuant to a Share Repurchase Agreement, dated June 13, 2024.

F2 · ownership.nature: The Reporting Person is a managing director of Goldman, Sachs & Co. ("Goldman Sachs"). Goldman Sachs is a subsidiary of The Goldman Sachs Group, Inc. ("GS Group"). GS Group is the direct owner of Broad Street Principal Investments, L.L.C., which directly holds 10,683,430 shares of Class A Common Stock of the Issuer, and Bridge Street Opportunity Advisors, L.L.C. is the general partner of each of StoneBridge 2017, L.P., which directly holds 1,597,531 shares of Class A Common Stock of the Issuer, and StoneBridge 2017 Offshore, L.P., which directly holds 566,259 shares of Class A Common Stock of the Issuer. Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 133,802 shares of Class A Common Stock of the Issuer. The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any.

SEC source: 0000895345-23-000211 · form4.xml · nonDerivative · entry 1

Gross Bradley J. · CIK 0001447253 · Director

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 16,980,553

F1 · ownership.nature: The Reporting Person is a managing director of Goldman, Sachs & Co. ("Goldman Sachs"). Goldman Sachs is a subsidiary of The Goldman Sachs Group, Inc. ("GS Group"). GS Group is the direct owner of BSPI, which directly holds 14,009,731 shares of Class A Common Stock of the Issuer, and Bridge Street Opportunity Advisors, L.L.C. ("Bridge Street") is the general partner of each of SB Employee Fund, which directly holds 2,094,924 shares of Class A Common Stock of the Issuer, and SB Employee Fund Offshore, which directly holds 742,565 shares of Class A Common Stock of the Issuer. Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 133,333 shares of Class A Common Stock of the Issuer. The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any.

SEC source: 0000895345-23-000202 · form4.xml · nonDerivative · entry 1

Gross Bradley J. · CIK 0001447253 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 17,099,784

F1 · ownership.nature: The Reporting Person is a managing director of Goldman, Sachs & Co. ("Goldman Sachs"). Goldman Sachs is a subsidiary of The Goldman Sachs Group, Inc. ("GS Group"). GS Group is the direct owner of BSPI, which directly holds 14,094,157 shares of Class A Common Stock of the Issuer, and Bridge Street Opportunity Advisors, L.L.C. ("Bridge Street") is the general partner of each of SB Employee Fund, which directly holds 425,953 shares of Class A Common Stock of the Issuer, and SB Employee Fund Offshore, which directly holds 2,428,636 shares of Class A Common Stock of the Issuer. Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 151,038 shares of Class A Common Stock of the Issuer. The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any.

SEC source: 0000895345-21-000953 · form4.xml · derivative · entry 2

Gross Bradley J. · CIK 0001447253 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See of Explanation of Responses

Disclosed balance after: 0

Underlying: Class A Common Stock · 20,948,746 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_price: On September 23, 2021, the 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Issuer (the "Series 8 Preferred Stock"), held in the aggregate by Broad Street Principal Investments, L.L.C. ("BSPI"), StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), converted automatically into 20,948,746 shares of Class A Common Stock of the Issuer and had no expiration date.

F1 · price: On September 23, 2021, the 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Issuer (the "Series 8 Preferred Stock"), held in the aggregate by Broad Street Principal Investments, L.L.C. ("BSPI"), StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), converted automatically into 20,948,746 shares of Class A Common Stock of the Issuer and had no expiration date.

F1 · derivative.exercise_date: On September 23, 2021, the 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Issuer (the "Series 8 Preferred Stock"), held in the aggregate by Broad Street Principal Investments, L.L.C. ("BSPI"), StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), converted automatically into 20,948,746 shares of Class A Common Stock of the Issuer and had no expiration date.

F1 · derivative.expiration_date: On September 23, 2021, the 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Issuer (the "Series 8 Preferred Stock"), held in the aggregate by Broad Street Principal Investments, L.L.C. ("BSPI"), StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), converted automatically into 20,948,746 shares of Class A Common Stock of the Issuer and had no expiration date.

F2 · ownership.nature: The Reporting Person is a managing director of Goldman, Sachs & Co. ("Goldman Sachs"). Goldman Sachs is a subsidiary of The Goldman Sachs Group, Inc. ("GS Group"). GS Group is the direct owner of BSPI, which directly holds 17,420,458 shares of Class A Common Stock of the Issuer following the conversion reported herein, Bridge Street Opportunity Advisors, L.L.C. ("Bridge Street") is the general partner of each of SB Employee Fund, which directly holds 923,346 shares of Class A Common Stock of the Issuer following the conversion reported herein, and SB Employee Fund Offshore, which directly holds 2,604,942 shares of Class A Common Stock of the Issuer following the conversion reported herein. Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 12,933.33 shares of Class A Common Stock of the Issuer.

F3 · ownership.nature: The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any.

SEC source: 0000895345-21-000953 · form4.xml · nonDerivative · entry 1

Gross Bradley J. · CIK 0001447253 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See of Explanation of Responses

Disclosed balance after: 20,961,679.33

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: On September 23, 2021, the 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Issuer (the "Series 8 Preferred Stock"), held in the aggregate by Broad Street Principal Investments, L.L.C. ("BSPI"), StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), converted automatically into 20,948,746 shares of Class A Common Stock of the Issuer and had no expiration date.

F2 · ownership.nature: The Reporting Person is a managing director of Goldman, Sachs & Co. ("Goldman Sachs"). Goldman Sachs is a subsidiary of The Goldman Sachs Group, Inc. ("GS Group"). GS Group is the direct owner of BSPI, which directly holds 17,420,458 shares of Class A Common Stock of the Issuer following the conversion reported herein, Bridge Street Opportunity Advisors, L.L.C. ("Bridge Street") is the general partner of each of SB Employee Fund, which directly holds 923,346 shares of Class A Common Stock of the Issuer following the conversion reported herein, and SB Employee Fund Offshore, which directly holds 2,604,942 shares of Class A Common Stock of the Issuer following the conversion reported herein. Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 12,933.33 shares of Class A Common Stock of the Issuer.

F3 · ownership.nature: The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any.

SEC source: 0000895345-21-000694 · form4.xml · derivative · entry 4

Gross Bradley J. · CIK 0001447253 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnoes

Disclosed balance after: 73,849

Underlying: Class A Common Stock · 20,953,333.15 shares

Expires not disclosed

F2 · derivative.exercise_price: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F4 · derivative.exercise_price: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · derivative.exercise_price: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · derivative.exercise_price: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · derivative.exercise_price: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · derivative.exercise_price: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

F2 · price: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F4 · price: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · price: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · price: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · price: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · price: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

F2 · derivative.exercise_date: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F3 · derivative.exercise_date: On March 6, 2017 BSPI assigned its right to purchase 11,813 and 4,187 Preference Shares of MDC Canada to StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), respectively, pursuant to two Assignment and Assumption Agreements. GS Group is the direct owner of BSPI and Bridge Street Opportunity Advisors, L.L.C. ("Bridge Street"). Bridge Street is the general partner of each Employee Fund.

F4 · derivative.exercise_date: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · derivative.exercise_date: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · derivative.exercise_date: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · derivative.exercise_date: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · derivative.exercise_date: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

F2 · derivative.expiration_date: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F3 · derivative.expiration_date: On March 6, 2017 BSPI assigned its right to purchase 11,813 and 4,187 Preference Shares of MDC Canada to StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), respectively, pursuant to two Assignment and Assumption Agreements. GS Group is the direct owner of BSPI and Bridge Street Opportunity Advisors, L.L.C. ("Bridge Street"). Bridge Street is the general partner of each Employee Fund.

F4 · derivative.expiration_date: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · derivative.expiration_date: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · derivative.expiration_date: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · derivative.expiration_date: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · derivative.expiration_date: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

F2 · derivative.underlying_shares: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F3 · derivative.underlying_shares: On March 6, 2017 BSPI assigned its right to purchase 11,813 and 4,187 Preference Shares of MDC Canada to StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), respectively, pursuant to two Assignment and Assumption Agreements. GS Group is the direct owner of BSPI and Bridge Street Opportunity Advisors, L.L.C. ("Bridge Street"). Bridge Street is the general partner of each Employee Fund.

F4 · derivative.underlying_shares: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · derivative.underlying_shares: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · derivative.underlying_shares: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · derivative.underlying_shares: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · derivative.underlying_shares: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

F2 · balance_after: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F3 · balance_after: On March 6, 2017 BSPI assigned its right to purchase 11,813 and 4,187 Preference Shares of MDC Canada to StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), respectively, pursuant to two Assignment and Assumption Agreements. GS Group is the direct owner of BSPI and Bridge Street Opportunity Advisors, L.L.C. ("Bridge Street"). Bridge Street is the general partner of each Employee Fund.

F4 · balance_after: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · balance_after: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · balance_after: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · balance_after: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · balance_after: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

F1 · ownership.nature: The Reporting Person is a managing director of Goldman, Sachs & Co. ("Goldman Sachs"). Goldman Sachs is a subsidiary of The Goldman Sachs Group, Inc. ("GS Group"). The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any.

F2 · ownership.nature: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F3 · ownership.nature: On March 6, 2017 BSPI assigned its right to purchase 11,813 and 4,187 Preference Shares of MDC Canada to StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), respectively, pursuant to two Assignment and Assumption Agreements. GS Group is the direct owner of BSPI and Bridge Street Opportunity Advisors, L.L.C. ("Bridge Street"). Bridge Street is the general partner of each Employee Fund.

F4 · ownership.nature: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · ownership.nature: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · ownership.nature: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · ownership.nature: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · ownership.nature: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

SEC source: 0000895345-21-000694 · form4.xml · derivative · entry 3

Gross Bradley J. · CIK 0001447253 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Class A Common Stock · 20,953,333.15 shares

Expires not disclosed

F2 · derivative.exercise_price: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F4 · derivative.exercise_price: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · derivative.exercise_price: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · derivative.exercise_price: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · derivative.exercise_price: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · derivative.exercise_price: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

F2 · price: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F4 · price: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · price: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · price: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · price: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · price: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

F2 · derivative.exercise_date: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F3 · derivative.exercise_date: On March 6, 2017 BSPI assigned its right to purchase 11,813 and 4,187 Preference Shares of MDC Canada to StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), respectively, pursuant to two Assignment and Assumption Agreements. GS Group is the direct owner of BSPI and Bridge Street Opportunity Advisors, L.L.C. ("Bridge Street"). Bridge Street is the general partner of each Employee Fund.

F4 · derivative.exercise_date: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · derivative.exercise_date: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · derivative.exercise_date: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · derivative.exercise_date: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · derivative.exercise_date: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

F2 · derivative.expiration_date: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F3 · derivative.expiration_date: On March 6, 2017 BSPI assigned its right to purchase 11,813 and 4,187 Preference Shares of MDC Canada to StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), respectively, pursuant to two Assignment and Assumption Agreements. GS Group is the direct owner of BSPI and Bridge Street Opportunity Advisors, L.L.C. ("Bridge Street"). Bridge Street is the general partner of each Employee Fund.

F4 · derivative.expiration_date: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · derivative.expiration_date: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · derivative.expiration_date: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · derivative.expiration_date: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · derivative.expiration_date: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

F2 · derivative.underlying_shares: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F3 · derivative.underlying_shares: On March 6, 2017 BSPI assigned its right to purchase 11,813 and 4,187 Preference Shares of MDC Canada to StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), respectively, pursuant to two Assignment and Assumption Agreements. GS Group is the direct owner of BSPI and Bridge Street Opportunity Advisors, L.L.C. ("Bridge Street"). Bridge Street is the general partner of each Employee Fund.

F4 · derivative.underlying_shares: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · derivative.underlying_shares: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · derivative.underlying_shares: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · derivative.underlying_shares: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · derivative.underlying_shares: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

F2 · balance_after: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F3 · balance_after: On March 6, 2017 BSPI assigned its right to purchase 11,813 and 4,187 Preference Shares of MDC Canada to StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), respectively, pursuant to two Assignment and Assumption Agreements. GS Group is the direct owner of BSPI and Bridge Street Opportunity Advisors, L.L.C. ("Bridge Street"). Bridge Street is the general partner of each Employee Fund.

F4 · balance_after: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · balance_after: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · balance_after: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · balance_after: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · balance_after: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

F1 · ownership.nature: The Reporting Person is a managing director of Goldman, Sachs & Co. ("Goldman Sachs"). Goldman Sachs is a subsidiary of The Goldman Sachs Group, Inc. ("GS Group"). The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any.

F2 · ownership.nature: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F3 · ownership.nature: On March 6, 2017 BSPI assigned its right to purchase 11,813 and 4,187 Preference Shares of MDC Canada to StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), respectively, pursuant to two Assignment and Assumption Agreements. GS Group is the direct owner of BSPI and Bridge Street Opportunity Advisors, L.L.C. ("Bridge Street"). Bridge Street is the general partner of each Employee Fund.

F4 · ownership.nature: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · ownership.nature: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · ownership.nature: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · ownership.nature: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · ownership.nature: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

SEC source: 0000895345-21-000694 · form4.xml · derivative · entry 2

Gross Bradley J. · CIK 0001447253 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Class A Common Stock · 6,001,218.02 shares

Expires not disclosed

F2 · derivative.exercise_price: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F4 · derivative.exercise_price: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · derivative.exercise_price: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · derivative.exercise_price: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · derivative.exercise_price: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · derivative.exercise_price: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

F2 · price: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F4 · price: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · price: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · price: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · price: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · price: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

F2 · derivative.exercise_date: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F3 · derivative.exercise_date: On March 6, 2017 BSPI assigned its right to purchase 11,813 and 4,187 Preference Shares of MDC Canada to StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), respectively, pursuant to two Assignment and Assumption Agreements. GS Group is the direct owner of BSPI and Bridge Street Opportunity Advisors, L.L.C. ("Bridge Street"). Bridge Street is the general partner of each Employee Fund.

F4 · derivative.exercise_date: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · derivative.exercise_date: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · derivative.exercise_date: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · derivative.exercise_date: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · derivative.exercise_date: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

F2 · derivative.expiration_date: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F3 · derivative.expiration_date: On March 6, 2017 BSPI assigned its right to purchase 11,813 and 4,187 Preference Shares of MDC Canada to StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), respectively, pursuant to two Assignment and Assumption Agreements. GS Group is the direct owner of BSPI and Bridge Street Opportunity Advisors, L.L.C. ("Bridge Street"). Bridge Street is the general partner of each Employee Fund.

F4 · derivative.expiration_date: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · derivative.expiration_date: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · derivative.expiration_date: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · derivative.expiration_date: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · derivative.expiration_date: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

F2 · derivative.underlying_shares: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F3 · derivative.underlying_shares: On March 6, 2017 BSPI assigned its right to purchase 11,813 and 4,187 Preference Shares of MDC Canada to StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), respectively, pursuant to two Assignment and Assumption Agreements. GS Group is the direct owner of BSPI and Bridge Street Opportunity Advisors, L.L.C. ("Bridge Street"). Bridge Street is the general partner of each Employee Fund.

F4 · derivative.underlying_shares: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · derivative.underlying_shares: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · derivative.underlying_shares: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · derivative.underlying_shares: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · derivative.underlying_shares: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

F2 · balance_after: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F3 · balance_after: On March 6, 2017 BSPI assigned its right to purchase 11,813 and 4,187 Preference Shares of MDC Canada to StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), respectively, pursuant to two Assignment and Assumption Agreements. GS Group is the direct owner of BSPI and Bridge Street Opportunity Advisors, L.L.C. ("Bridge Street"). Bridge Street is the general partner of each Employee Fund.

F4 · balance_after: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · balance_after: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · balance_after: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · balance_after: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · balance_after: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

F1 · ownership.nature: The Reporting Person is a managing director of Goldman, Sachs & Co. ("Goldman Sachs"). Goldman Sachs is a subsidiary of The Goldman Sachs Group, Inc. ("GS Group"). The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any.

F2 · ownership.nature: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F3 · ownership.nature: On March 6, 2017 BSPI assigned its right to purchase 11,813 and 4,187 Preference Shares of MDC Canada to StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), respectively, pursuant to two Assignment and Assumption Agreements. GS Group is the direct owner of BSPI and Bridge Street Opportunity Advisors, L.L.C. ("Bridge Street"). Bridge Street is the general partner of each Employee Fund.

F4 · ownership.nature: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · ownership.nature: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · ownership.nature: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · ownership.nature: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · ownership.nature: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

SEC source: 0000895345-21-000694 · form4.xml · nonDerivative · entry 1

Gross Bradley J. · CIK 0001447253 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 20,991,737.48

F2 · shares: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F3 · shares: On March 6, 2017 BSPI assigned its right to purchase 11,813 and 4,187 Preference Shares of MDC Canada to StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), respectively, pursuant to two Assignment and Assumption Agreements. GS Group is the direct owner of BSPI and Bridge Street Opportunity Advisors, L.L.C. ("Bridge Street"). Bridge Street is the general partner of each Employee Fund.

F4 · shares: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · shares: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · shares: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · shares: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · shares: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

F2 · price: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F4 · price: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · price: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · price: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · price: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · price: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

F2 · balance_after: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F3 · balance_after: On March 6, 2017 BSPI assigned its right to purchase 11,813 and 4,187 Preference Shares of MDC Canada to StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), respectively, pursuant to two Assignment and Assumption Agreements. GS Group is the direct owner of BSPI and Bridge Street Opportunity Advisors, L.L.C. ("Bridge Street"). Bridge Street is the general partner of each Employee Fund.

F4 · balance_after: In December 2020, MDC Canada and Stagwell Media LP ("Stagwell") entered into a transaction agreement (the "Transaction Agreement"), providing for, among other things, the redomiciliation (the "Redomiciliation") of MDC Canada from the federal jurisdiction of Canada to the State of Delaware and the subsequent combination (the "Business Combination") of MDC Canada's business with the business of the subsidiaries of Stagwell that own and operate a portfolio of marketing services companies. The Redomiciliation, the Business Combination, and a series of related transactions are referred to herein as the "Transactions", and following such Business Combination, the combined company is referred to herein as the "Combined Company" or the "Issuer".

F5 · balance_after: In connection with the consummation of the Transactions, each Class A Subordinate Voting Share of MDC Canada was converted into one share of Class A common stock, par value $0.001 per share of the Combined Company ("Class A Common Stock"), and each Series 4 Preference Share of MDC Canada was converted into a share of Series 4 Convertible Preferred Stock, par value $0.001 per share of the Combined Company ("Series 4 Preferred Stock").

F6 · balance_after: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · balance_after: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · balance_after: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

F1 · ownership.nature: The Reporting Person is a managing director of Goldman, Sachs & Co. ("Goldman Sachs"). Goldman Sachs is a subsidiary of The Goldman Sachs Group, Inc. ("GS Group"). The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any.

F2 · ownership.nature: On February 14, 2017 MDC Partners Inc. ("MDC Canada") and Broad Street Principal Investments, L.L.C. ("BSPI") entered into a Securities Purchase Agreement (as amended from time to time, the "Purchase Agreement"), pursuant to which MDC Canada agreed to issue and BSPI agreed to purchase (the "Private Placement") 95,000 Series 4 Convertible Preference Shares of MDC Canada (the "Preference Shares").

F3 · ownership.nature: On March 6, 2017 BSPI assigned its right to purchase 11,813 and 4,187 Preference Shares of MDC Canada to StoneBridge 2017, L.P., a Delaware limited partnership ("SB Employee Fund") and StoneBridge 2017 Offshore, L.P., a Cayman Islands exempted limited partnership ("SB Employee Fund Offshore," and together with SB Employee Fund, the "Employee Funds"), respectively, pursuant to two Assignment and Assumption Agreements. GS Group is the direct owner of BSPI and Bridge Street Opportunity Advisors, L.L.C. ("Bridge Street"). Bridge Street is the general partner of each Employee Fund.

F6 · ownership.nature: In connection with the closing of the Transactions, on August 4, 2021, (i) the Issuer redeemed 21,151 shares of Series 4 Preferred Stock from BSPI and the Employee Funds (which were convertible into 6,001,218.02 shares of Class A Common Stock) in exchange for $25 million in cash, and (ii) BSPI and the Employee Funds delivered to the issuer, and the Issuer accepted from BSPI and the Employee Funds, 73,849 shares of Series 4 Preferred Stock (which were convertible into 20,953,333.15 shares of Class A Common Stock) in exchange for the issuance to the Holders of 73,849 shares of Series 8 Convertible Preferred Stock, par value $0.001 per share of the Combined Company (the "Series 8 Preferred Stock") having the terms set forth in the certificate of designation designating the Series 8 Preferred Stock.

F7 · ownership.nature: BSPI and the Employee Funds have the right to convert the Series 8 Preferred Stock into shares of Class A Common Stock in whole at any time and from time to time, and in part at any time and from time to time, subject to certain ownership limitations.

F8 · ownership.nature: Because of the relationship by and between GS Group, Goldman Sachs, BSPI and the Employee Funds, GS Group and Goldman Sachs may be deemed (for purposes of Rule 13d-3(a) and Rule 16a-1(a) only and not for any other applicable purpose) to beneficially own an aggregate of 20,991,737.48 shares of Class A Common Stock, consisting of (i) 17,424,273.07 shares of Class A Common Stock (deliverable to BSPI upon conversion of the Series 8 Preferred Stock directly held by BSPI), (ii) 3,529,060.08 shares of Class A Common Stock (deliverable to the Employee Funds upon conversion of the Series 8 Preferred Stock directly held by the Employee Funds), and (iii) Goldman Sachs beneficially owns directly and GS Group may be deemed to beneficially own indirectly 38,404.33 shares of Class A Common Stock.

SEC source: 0000899243-21-031373 · doc4.xml · nonDerivative · entry 6

Gross Bradley J. · CIK 0001447253 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 7,703

F1 · security: These transactions in the Class A Subordinate Voting Shares (the "Class A Shares") of MDC Partners Inc. (the "Issuer") have not previously been reported on Form 4 and were effected by Goldman Sachs & Co. LLC ("Goldman Sachs") acting as agent on behalf of certain international affiliates that had entered into riskless principal trades in connection with client trade facilitation in the ordinary course of their business.

F2 · security: Without conceding riskless principal trades in connection with client trade facilitation in the ordinary course of business can result in liability under Section 16(b) of the Securities Exchange Act of 1934 (the "Exchange Act"), the amount of profit potentially recoverable by the Issuer from the reported transactions in the event that they were subject to Section 16(b) will be remitted to the Issuer.

F3 · security: The Reporting Person is a managing director of Goldman Sachs. Goldman Sachs is a subsidiary of by The Goldman Sachs Group, Inc. ("GS Group").

F4 · balance_after: Goldman Sachs and GS Group may be deemed to beneficially own 7,703 Class A Shares acquired by Goldman Sachs or another wholly-owned broker or dealer subsidiary of GS Group in ordinary course trading activities.

F5 · balance_after: The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of, or has any pecuniary interest in, such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.

F4 · ownership.nature: Goldman Sachs and GS Group may be deemed to beneficially own 7,703 Class A Shares acquired by Goldman Sachs or another wholly-owned broker or dealer subsidiary of GS Group in ordinary course trading activities.

F5 · ownership.nature: The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of, or has any pecuniary interest in, such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.

SEC source: 0000899243-21-031373 · doc4.xml · nonDerivative · entry 5

Gross Bradley J. · CIK 0001447253 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 12,316

F1 · security: These transactions in the Class A Subordinate Voting Shares (the "Class A Shares") of MDC Partners Inc. (the "Issuer") have not previously been reported on Form 4 and were effected by Goldman Sachs & Co. LLC ("Goldman Sachs") acting as agent on behalf of certain international affiliates that had entered into riskless principal trades in connection with client trade facilitation in the ordinary course of their business.

F2 · security: Without conceding riskless principal trades in connection with client trade facilitation in the ordinary course of business can result in liability under Section 16(b) of the Securities Exchange Act of 1934 (the "Exchange Act"), the amount of profit potentially recoverable by the Issuer from the reported transactions in the event that they were subject to Section 16(b) will be remitted to the Issuer.

F3 · security: The Reporting Person is a managing director of Goldman Sachs. Goldman Sachs is a subsidiary of by The Goldman Sachs Group, Inc. ("GS Group").

F4 · balance_after: Goldman Sachs and GS Group may be deemed to beneficially own 7,703 Class A Shares acquired by Goldman Sachs or another wholly-owned broker or dealer subsidiary of GS Group in ordinary course trading activities.

F5 · balance_after: The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of, or has any pecuniary interest in, such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.

F4 · ownership.nature: Goldman Sachs and GS Group may be deemed to beneficially own 7,703 Class A Shares acquired by Goldman Sachs or another wholly-owned broker or dealer subsidiary of GS Group in ordinary course trading activities.

F5 · ownership.nature: The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of, or has any pecuniary interest in, such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.

SEC source: 0000899243-21-031373 · doc4.xml · nonDerivative · entry 4

Gross Bradley J. · CIK 0001447253 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 7,639

F1 · security: These transactions in the Class A Subordinate Voting Shares (the "Class A Shares") of MDC Partners Inc. (the "Issuer") have not previously been reported on Form 4 and were effected by Goldman Sachs & Co. LLC ("Goldman Sachs") acting as agent on behalf of certain international affiliates that had entered into riskless principal trades in connection with client trade facilitation in the ordinary course of their business.

F2 · security: Without conceding riskless principal trades in connection with client trade facilitation in the ordinary course of business can result in liability under Section 16(b) of the Securities Exchange Act of 1934 (the "Exchange Act"), the amount of profit potentially recoverable by the Issuer from the reported transactions in the event that they were subject to Section 16(b) will be remitted to the Issuer.

F3 · security: The Reporting Person is a managing director of Goldman Sachs. Goldman Sachs is a subsidiary of by The Goldman Sachs Group, Inc. ("GS Group").

F4 · balance_after: Goldman Sachs and GS Group may be deemed to beneficially own 7,703 Class A Shares acquired by Goldman Sachs or another wholly-owned broker or dealer subsidiary of GS Group in ordinary course trading activities.

F5 · balance_after: The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of, or has any pecuniary interest in, such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.

F4 · ownership.nature: Goldman Sachs and GS Group may be deemed to beneficially own 7,703 Class A Shares acquired by Goldman Sachs or another wholly-owned broker or dealer subsidiary of GS Group in ordinary course trading activities.

F5 · ownership.nature: The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of, or has any pecuniary interest in, such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.

SEC source: 0000899243-21-031373 · doc4.xml · nonDerivative · entry 3

Gross Bradley J. · CIK 0001447253 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 25,899

F1 · security: These transactions in the Class A Subordinate Voting Shares (the "Class A Shares") of MDC Partners Inc. (the "Issuer") have not previously been reported on Form 4 and were effected by Goldman Sachs & Co. LLC ("Goldman Sachs") acting as agent on behalf of certain international affiliates that had entered into riskless principal trades in connection with client trade facilitation in the ordinary course of their business.

F2 · security: Without conceding riskless principal trades in connection with client trade facilitation in the ordinary course of business can result in liability under Section 16(b) of the Securities Exchange Act of 1934 (the "Exchange Act"), the amount of profit potentially recoverable by the Issuer from the reported transactions in the event that they were subject to Section 16(b) will be remitted to the Issuer.

F3 · security: The Reporting Person is a managing director of Goldman Sachs. Goldman Sachs is a subsidiary of by The Goldman Sachs Group, Inc. ("GS Group").

F4 · balance_after: Goldman Sachs and GS Group may be deemed to beneficially own 7,703 Class A Shares acquired by Goldman Sachs or another wholly-owned broker or dealer subsidiary of GS Group in ordinary course trading activities.

F5 · balance_after: The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of, or has any pecuniary interest in, such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.

F4 · ownership.nature: Goldman Sachs and GS Group may be deemed to beneficially own 7,703 Class A Shares acquired by Goldman Sachs or another wholly-owned broker or dealer subsidiary of GS Group in ordinary course trading activities.

F5 · ownership.nature: The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of, or has any pecuniary interest in, such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.

SEC source: 0000899243-21-031373 · doc4.xml · nonDerivative · entry 2

Gross Bradley J. · CIK 0001447253 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 7,636

F1 · security: These transactions in the Class A Subordinate Voting Shares (the "Class A Shares") of MDC Partners Inc. (the "Issuer") have not previously been reported on Form 4 and were effected by Goldman Sachs & Co. LLC ("Goldman Sachs") acting as agent on behalf of certain international affiliates that had entered into riskless principal trades in connection with client trade facilitation in the ordinary course of their business.

F2 · security: Without conceding riskless principal trades in connection with client trade facilitation in the ordinary course of business can result in liability under Section 16(b) of the Securities Exchange Act of 1934 (the "Exchange Act"), the amount of profit potentially recoverable by the Issuer from the reported transactions in the event that they were subject to Section 16(b) will be remitted to the Issuer.

F3 · security: The Reporting Person is a managing director of Goldman Sachs. Goldman Sachs is a subsidiary of by The Goldman Sachs Group, Inc. ("GS Group").

F4 · balance_after: Goldman Sachs and GS Group may be deemed to beneficially own 7,703 Class A Shares acquired by Goldman Sachs or another wholly-owned broker or dealer subsidiary of GS Group in ordinary course trading activities.

F5 · balance_after: The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of, or has any pecuniary interest in, such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.

F4 · ownership.nature: Goldman Sachs and GS Group may be deemed to beneficially own 7,703 Class A Shares acquired by Goldman Sachs or another wholly-owned broker or dealer subsidiary of GS Group in ordinary course trading activities.

F5 · ownership.nature: The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of, or has any pecuniary interest in, such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.

SEC source: 0000899243-21-031373 · doc4.xml · nonDerivative · entry 1

Gross Bradley J. · CIK 0001447253 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 16,523

F1 · security: These transactions in the Class A Subordinate Voting Shares (the "Class A Shares") of MDC Partners Inc. (the "Issuer") have not previously been reported on Form 4 and were effected by Goldman Sachs & Co. LLC ("Goldman Sachs") acting as agent on behalf of certain international affiliates that had entered into riskless principal trades in connection with client trade facilitation in the ordinary course of their business.

F2 · security: Without conceding riskless principal trades in connection with client trade facilitation in the ordinary course of business can result in liability under Section 16(b) of the Securities Exchange Act of 1934 (the "Exchange Act"), the amount of profit potentially recoverable by the Issuer from the reported transactions in the event that they were subject to Section 16(b) will be remitted to the Issuer.

F3 · security: The Reporting Person is a managing director of Goldman Sachs. Goldman Sachs is a subsidiary of by The Goldman Sachs Group, Inc. ("GS Group").

F4 · balance_after: Goldman Sachs and GS Group may be deemed to beneficially own 7,703 Class A Shares acquired by Goldman Sachs or another wholly-owned broker or dealer subsidiary of GS Group in ordinary course trading activities.

F5 · balance_after: The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of, or has any pecuniary interest in, such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.

F4 · ownership.nature: Goldman Sachs and GS Group may be deemed to beneficially own 7,703 Class A Shares acquired by Goldman Sachs or another wholly-owned broker or dealer subsidiary of GS Group in ordinary course trading activities.

F5 · ownership.nature: The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of, or has any pecuniary interest in, such securities for purposes of Section 16 of the Exchange Act, or for any other purpose.

SEC source: 0001140361-18-003293 · doc1.xml · derivative · entry 4

Gross Bradley J. · CIK 0001447253 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 0

Underlying: Common Shares · 28,808,224 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F4 · derivative.exercise_price: On January 23, 2018, in connection with the consummation of the initial public offering (the "IPO") of the Company, all of the 325,000 5.00% Series B Cumulative Convertible Voting Preferred Shares (the "Series B Preferred Shares") of the Company held by certain investment partnerships (the "GS Investors") were converted (the "Conversion") into an aggregate of 28,808,224 Common Shares of the Company and the payment of cash in lieu of fractional shares.

F4 · price: On January 23, 2018, in connection with the consummation of the initial public offering (the "IPO") of the Company, all of the 325,000 5.00% Series B Cumulative Convertible Voting Preferred Shares (the "Series B Preferred Shares") of the Company held by certain investment partnerships (the "GS Investors") were converted (the "Conversion") into an aggregate of 28,808,224 Common Shares of the Company and the payment of cash in lieu of fractional shares.

F4 · derivative.exercise_date: On January 23, 2018, in connection with the consummation of the initial public offering (the "IPO") of the Company, all of the 325,000 5.00% Series B Cumulative Convertible Voting Preferred Shares (the "Series B Preferred Shares") of the Company held by certain investment partnerships (the "GS Investors") were converted (the "Conversion") into an aggregate of 28,808,224 Common Shares of the Company and the payment of cash in lieu of fractional shares.

F4 · derivative.expiration_date: On January 23, 2018, in connection with the consummation of the initial public offering (the "IPO") of the Company, all of the 325,000 5.00% Series B Cumulative Convertible Voting Preferred Shares (the "Series B Preferred Shares") of the Company held by certain investment partnerships (the "GS Investors") were converted (the "Conversion") into an aggregate of 28,808,224 Common Shares of the Company and the payment of cash in lieu of fractional shares.

F1 · ownership.nature: The Reporting Person is a managing director of Goldman Sachs & Co. LLC ("Goldman Sachs"). Goldman Sachs is a subsidiary of The Goldman Sachs Group, Inc. ("GS Group"). The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of, or has any pecuniary interest in, such securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.

F4 · ownership.nature: On January 23, 2018, in connection with the consummation of the initial public offering (the "IPO") of the Company, all of the 325,000 5.00% Series B Cumulative Convertible Voting Preferred Shares (the "Series B Preferred Shares") of the Company held by certain investment partnerships (the "GS Investors") were converted (the "Conversion") into an aggregate of 28,808,224 Common Shares of the Company and the payment of cash in lieu of fractional shares.

F7 · ownership.nature: As of January 23, 2018, as a result of the Purchase, Goldman Sachs beneficially owns directly, and GS Group may be deemed to beneficially own indirectly, 125,000 Common Shares, and as a result of the Conversion, the IPO, and the Over-Allotment Option, both Goldman Sachs and GS Group may be deemed to beneficially own indirectly, in the aggregate, 23,644,508 Common Shares owned by the GS Investors because affiliates of Goldman Sachs and GS Group are the general partner, managing limited partner, managing general partner, managing partner, managing member or member of each of the GS Investors. Goldman Sachs is a subsidiary of GS Group. Goldman Sachs is the investment manager of certain of the GS Investors.

SEC source: 0001140361-18-003293 · doc1.xml · nonDerivative · entry 3

Gross Bradley J. · CIK 0001447253 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 23,769,508

F5 · shares: In connection with the IPO, pursuant to an underwriting agreement (the "Underwriting Agreement") and final prospectus, each dated January 18, 2018, the GS Investors as selling shareholders, sold 4,490,188 Common Shares at $14.904 per share, which represents the $16.00 IPO price per Common Share, less the underwriting discount of $1.096 per Common Share. The IPO closed on January 23, 2018.

F6 · shares: In connection with the IPO and pursuant to the Underwriting Agreement, the underwriters exercised their option (the "Over-Allotment Option") to purchase additional Common Shares from the selling shareholders. The Over-Allotment Option closed simultaneously with the IPO on January 23, 2018. The GS Investors sold an additional 673,528 Common Shares pursuant to the underwriters' exercise of the Over-Allotment Option.

F5 · price: In connection with the IPO, pursuant to an underwriting agreement (the "Underwriting Agreement") and final prospectus, each dated January 18, 2018, the GS Investors as selling shareholders, sold 4,490,188 Common Shares at $14.904 per share, which represents the $16.00 IPO price per Common Share, less the underwriting discount of $1.096 per Common Share. The IPO closed on January 23, 2018.

F1 · ownership.nature: The Reporting Person is a managing director of Goldman Sachs & Co. LLC ("Goldman Sachs"). Goldman Sachs is a subsidiary of The Goldman Sachs Group, Inc. ("GS Group"). The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of, or has any pecuniary interest in, such securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.

F5 · ownership.nature: In connection with the IPO, pursuant to an underwriting agreement (the "Underwriting Agreement") and final prospectus, each dated January 18, 2018, the GS Investors as selling shareholders, sold 4,490,188 Common Shares at $14.904 per share, which represents the $16.00 IPO price per Common Share, less the underwriting discount of $1.096 per Common Share. The IPO closed on January 23, 2018.

F6 · ownership.nature: In connection with the IPO and pursuant to the Underwriting Agreement, the underwriters exercised their option (the "Over-Allotment Option") to purchase additional Common Shares from the selling shareholders. The Over-Allotment Option closed simultaneously with the IPO on January 23, 2018. The GS Investors sold an additional 673,528 Common Shares pursuant to the underwriters' exercise of the Over-Allotment Option.

F7 · ownership.nature: As of January 23, 2018, as a result of the Purchase, Goldman Sachs beneficially owns directly, and GS Group may be deemed to beneficially own indirectly, 125,000 Common Shares, and as a result of the Conversion, the IPO, and the Over-Allotment Option, both Goldman Sachs and GS Group may be deemed to beneficially own indirectly, in the aggregate, 23,644,508 Common Shares owned by the GS Investors because affiliates of Goldman Sachs and GS Group are the general partner, managing limited partner, managing general partner, managing partner, managing member or member of each of the GS Investors. Goldman Sachs is a subsidiary of GS Group. Goldman Sachs is the investment manager of certain of the GS Investors.

SEC source: 0001140361-18-003293 · doc1.xml · nonDerivative · entry 2

Gross Bradley J. · CIK 0001447253 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 28,933,224

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F4 · price: On January 23, 2018, in connection with the consummation of the initial public offering (the "IPO") of the Company, all of the 325,000 5.00% Series B Cumulative Convertible Voting Preferred Shares (the "Series B Preferred Shares") of the Company held by certain investment partnerships (the "GS Investors") were converted (the "Conversion") into an aggregate of 28,808,224 Common Shares of the Company and the payment of cash in lieu of fractional shares.

F1 · ownership.nature: The Reporting Person is a managing director of Goldman Sachs & Co. LLC ("Goldman Sachs"). Goldman Sachs is a subsidiary of The Goldman Sachs Group, Inc. ("GS Group"). The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of, or has any pecuniary interest in, such securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.

F4 · ownership.nature: On January 23, 2018, in connection with the consummation of the initial public offering (the "IPO") of the Company, all of the 325,000 5.00% Series B Cumulative Convertible Voting Preferred Shares (the "Series B Preferred Shares") of the Company held by certain investment partnerships (the "GS Investors") were converted (the "Conversion") into an aggregate of 28,808,224 Common Shares of the Company and the payment of cash in lieu of fractional shares.

F7 · ownership.nature: As of January 23, 2018, as a result of the Purchase, Goldman Sachs beneficially owns directly, and GS Group may be deemed to beneficially own indirectly, 125,000 Common Shares, and as a result of the Conversion, the IPO, and the Over-Allotment Option, both Goldman Sachs and GS Group may be deemed to beneficially own indirectly, in the aggregate, 23,644,508 Common Shares owned by the GS Investors because affiliates of Goldman Sachs and GS Group are the general partner, managing limited partner, managing general partner, managing partner, managing member or member of each of the GS Investors. Goldman Sachs is a subsidiary of GS Group. Goldman Sachs is the investment manager of certain of the GS Investors.

SEC source: 0001140361-18-003293 · doc1.xml · nonDerivative · entry 1

Gross Bradley J. · CIK 0001447253 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 125,000

F2 · shares: On January 19, 2018, 125,000 of the common shares, par value $0.01 per share (the "Common Shares"), of Americold Realty Trust (the "Company") reported herein as indirectly purchased (the "Purchase") were beneficially owned directly by Goldman Sachs and indirectly by GS Group.

F3 · price: Reflects a weighted average purchase price of $17.40 per share, at prices ranging from $17.14 to $17.50 per share. The Reporting Person will provide, upon request by the staff of the Securities and Exchange Commission, the Company, or a security holder of the Company, full information regarding the number of shares purchased at each separate price.

F1 · ownership.nature: The Reporting Person is a managing director of Goldman Sachs & Co. LLC ("Goldman Sachs"). Goldman Sachs is a subsidiary of The Goldman Sachs Group, Inc. ("GS Group"). The Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of, or has any pecuniary interest in, such securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.

F2 · ownership.nature: On January 19, 2018, 125,000 of the common shares, par value $0.01 per share (the "Common Shares"), of Americold Realty Trust (the "Company") reported herein as indirectly purchased (the "Purchase") were beneficially owned directly by Goldman Sachs and indirectly by GS Group.

F3 · ownership.nature: Reflects a weighted average purchase price of $17.40 per share, at prices ranging from $17.14 to $17.50 per share. The Reporting Person will provide, upon request by the staff of the Securities and Exchange Commission, the Company, or a security holder of the Company, full information regarding the number of shares purchased at each separate price.

F7 · ownership.nature: As of January 23, 2018, as a result of the Purchase, Goldman Sachs beneficially owns directly, and GS Group may be deemed to beneficially own indirectly, 125,000 Common Shares, and as a result of the Conversion, the IPO, and the Over-Allotment Option, both Goldman Sachs and GS Group may be deemed to beneficially own indirectly, in the aggregate, 23,644,508 Common Shares owned by the GS Investors because affiliates of Goldman Sachs and GS Group are the general partner, managing limited partner, managing general partner, managing partner, managing member or member of each of the GS Investors. Goldman Sachs is a subsidiary of GS Group. Goldman Sachs is the investment manager of certain of the GS Investors.