Vanderhook Christopher

SEC source: 0001843104-26-000016 · wk-form4_1789428818.xml · nonDerivative · entry 1

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 285,244

F1 · shares: Represents shares repurchased by the Issuer from the Reporting Person in the amount of estimated taxes to be paid by the Reporting Person in connection with the vesting of 16,198 restricted stock units on September 10, 2026.

SEC source: 0001843104-26-000014 · wk-form4_1784858061.xml · nonDerivative · entry 5

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 0

F4 · kind: Shares sold pursuant to a 10b5-1 plan adopted by Capital V LLC on March 18, 2025, as amended on September 17, 2025.

F7 · price: The price reported in Column 4 is a weighted average price, based on the Reporting Person's pro rata portion of a total of 12,912 shares of Class A Common Stock sold on behalf of Capital V LLC. These shares were sold in multiple transactions at prices ranging from $10.17 to $10.81. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000014 · wk-form4_1784858061.xml · nonDerivative · entry 4

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 4,304

F4 · kind: Shares sold pursuant to a 10b5-1 plan adopted by Capital V LLC on March 18, 2025, as amended on September 17, 2025.

F6 · price: The price reported in Column 4 is a weighted average price, based on the Reporting Person's pro rata portion of a total of 15,000 shares of Class A Common Stock sold on behalf of Capital V LLC. These shares were sold in multiple transactions at prices ranging from $10.77 to $11.69. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000014 · wk-form4_1784858061.xml · derivative · entry 6

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 9,069,775

Underlying: Class A Common Stock · 12,500 shares

Expires not disclosed

F1 · derivative.exercise_price: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A Common Stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B Common Stock will be automatically cancelled.

F1 · price: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A Common Stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B Common Stock will be automatically cancelled.

F1 · derivative.exercise_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A Common Stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B Common Stock will be automatically cancelled.

F1 · derivative.expiration_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A Common Stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B Common Stock will be automatically cancelled.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000014 · wk-form4_1784858061.xml · nonDerivative · entry 3

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 9,304

F4 · kind: Shares sold pursuant to a 10b5-1 plan adopted by Capital V LLC on March 18, 2025, as amended on September 17, 2025.

F5 · price: The price reported in Column 4 is a weighted average price, based on the Reporting Person's pro rata portion of a total of 9,588 shares of Class A Common Stock sold on behalf of Capital V LLC. These shares were sold in multiple transactions at prices ranging from $11.53 to $12.03. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000014 · wk-form4_1784858061.xml · nonDerivative · entry 2

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 9,069,775

F3 · kind: Reflects the cancellation for no consideration of a number of shares of Class B common stock of the Issuer in connection with the redemption by Capital V LLC of an equal number of Class B Units for Class A common stock.

F3 · price: Reflects the cancellation for no consideration of a number of shares of Class B common stock of the Issuer in connection with the redemption by Capital V LLC of an equal number of Class B Units for Class A common stock.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000014 · wk-form4_1784858061.xml · nonDerivative · entry 1

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 12,500

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 · kind: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A Common Stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B Common Stock will be automatically cancelled.

F1 · price: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A Common Stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B Common Stock will be automatically cancelled.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000013 · wk-form4_1781824130.xml · nonDerivative · entry 5

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 0

F4 · kind: Shares sold pursuant to a 10b5-1 plan adopted by Capital V LLC on March 18, 2025, as amended on September 17, 2025.

F7 · price: The price reported in Column 4 is a weighted average price, based on the Reporting Person's pro rata portion of a total of 7,500 shares of Class A Common Stock sold on behalf of Capital V LLC. These shares were sold in multiple transactions at prices ranging from $10.665 to $11.23. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000013 · wk-form4_1781824130.xml · nonDerivative · entry 4

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 2,500

F4 · kind: Shares sold pursuant to a 10b5-1 plan adopted by Capital V LLC on March 18, 2025, as amended on September 17, 2025.

F6 · price: The price reported in Column 4 is a weighted average price, based on the Reporting Person's pro rata portion of a total of 15,000 shares of Class A Common Stock sold on behalf of Capital V LLC. These shares were sold in multiple transactions at prices ranging from $10.91 to $11.50. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000013 · wk-form4_1781824130.xml · derivative · entry 6

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 9,082,275

Underlying: Class A Common Stock · 12,500 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: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F1 · price: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F1 · derivative.exercise_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F1 · derivative.expiration_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000013 · wk-form4_1781824130.xml · nonDerivative · entry 3

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 7,500

F4 · kind: Shares sold pursuant to a 10b5-1 plan adopted by Capital V LLC on March 18, 2025, as amended on September 17, 2025.

F5 · price: The price reported in Column 4 is a weighted average price, based on the Reporting Person's pro rata portion of a total of 15,000 shares of Class A Common Stock sold on behalf of Capital V LLC. These shares were sold in multiple transactions at prices ranging from $10.77 to $11.43. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000013 · wk-form4_1781824130.xml · nonDerivative · entry 2

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 9,082,275

F3 · kind: Reflects the cancellation for no consideration of a number of shares of Class B common stock of the Issuer in connection with the redemption by Capital V LLC of an equal number of Class B Units for Class A common stock.

F3 · price: Reflects the cancellation for no consideration of a number of shares of Class B common stock of the Issuer in connection with the redemption by Capital V LLC of an equal number of Class B Units for Class A common stock.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000013 · wk-form4_1781824130.xml · nonDerivative · entry 1

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 12,500

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 · kind: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F1 · price: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001828791-26-000058 · wk-form4_1781570511.xml · nonDerivative · entry 1

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 293,880

F1 · kind: Shares were sold in a transaction instituted by the Issuer on the Reporting Person's behalf to cover estimated taxes associated with the vesting and settlement of restricted stock units.

SEC source: 0001843104-26-000012 · wk-form4_1781135953.xml · derivative · entry 18

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · Colbie Vanderhook Gift Trust

Disclosed balance after: 52,096

Underlying: Class A Common Stock · 52,096 shares

Expires not disclosed

F7 · derivative.exercise_price: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F7 · derivative.exercise_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F7 · derivative.expiration_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

SEC source: 0001843104-26-000012 · wk-form4_1781135953.xml · derivative · entry 17

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · Clay Vanderhook Gift Trust

Disclosed balance after: 52,096

Underlying: Class A Common Stock · 52,096 shares

Expires not disclosed

F7 · derivative.exercise_price: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F7 · derivative.exercise_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F7 · derivative.expiration_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

SEC source: 0001843104-26-000012 · wk-form4_1781135953.xml · derivative · entry 16

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · Carter Vanderhook Gift Trust

Disclosed balance after: 52,096

Underlying: Class A Common Stock · 52,096 shares

Expires not disclosed

F7 · derivative.exercise_price: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F7 · derivative.exercise_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F7 · derivative.expiration_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

SEC source: 0001843104-26-000012 · wk-form4_1781135953.xml · derivative · entry 15

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · Hayden Vanderhook Gift Trust

Disclosed balance after: 52,096

Underlying: Class A Common Stock · 52,096 shares

Expires not disclosed

F7 · derivative.exercise_price: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F7 · derivative.exercise_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F7 · derivative.expiration_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

SEC source: 0001843104-26-000012 · wk-form4_1781135953.xml · derivative · entry 14

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · By GRAT

Disclosed balance after: 0

Underlying: Class A Common Stock · 52,096 shares

Expires not disclosed

F7 · derivative.exercise_price: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F7 · derivative.exercise_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F7 · derivative.expiration_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F1 · balance_after: In addition to the gift transactions reported herein, reflects annuity payments by the GRATs to the Reporting Person pursuant to the terms of the GRAT, which annuity payments were exempt from reporting pursuant to Rule 16a-13.

F5 · ownership.nature: Securities held by the Colbie Vanderhook 2024 grantor retained annuity trust.

SEC source: 0001843104-26-000012 · wk-form4_1781135953.xml · derivative · entry 13

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · By GRAT

Disclosed balance after: 0

Underlying: Class A Common Stock · 52,096 shares

Expires not disclosed

F7 · derivative.exercise_price: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F7 · derivative.exercise_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F7 · derivative.expiration_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F1 · balance_after: In addition to the gift transactions reported herein, reflects annuity payments by the GRATs to the Reporting Person pursuant to the terms of the GRAT, which annuity payments were exempt from reporting pursuant to Rule 16a-13.

F4 · ownership.nature: Securities held by the Clay Vanderhook 2024 grantor retained annuity trust.

SEC source: 0001843104-26-000012 · wk-form4_1781135953.xml · derivative · entry 12

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · By GRAT

Disclosed balance after: 0

Underlying: Class A Common Stock · 52,096 shares

Expires not disclosed

F7 · derivative.exercise_price: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F7 · derivative.exercise_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F7 · derivative.expiration_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F1 · balance_after: In addition to the gift transactions reported herein, reflects annuity payments by the GRATs to the Reporting Person pursuant to the terms of the GRAT, which annuity payments were exempt from reporting pursuant to Rule 16a-13.

F3 · ownership.nature: Securities held by the Carter Vanderhook 2024 grantor retained annuity trust.

SEC source: 0001843104-26-000012 · wk-form4_1781135953.xml · derivative · entry 11

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · By GRAT

Disclosed balance after: 0

Underlying: Class A Common Stock · 52,096 shares

Expires not disclosed

F7 · derivative.exercise_price: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F7 · derivative.exercise_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F7 · derivative.expiration_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F1 · balance_after: In addition to the gift transactions reported herein, reflects annuity payments by the GRATs to the Reporting Person pursuant to the terms of the GRAT, which annuity payments were exempt from reporting pursuant to Rule 16a-13.

F2 · ownership.nature: Securities held by the Hayden Vanderhook 2024 grantor retained annuity trust.

SEC source: 0001843104-26-000012 · wk-form4_1781135953.xml · nonDerivative · entry 8

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · Colbie Vanderhook Gift Trust

Disclosed balance after: 52,096

SEC source: 0001843104-26-000012 · wk-form4_1781135953.xml · nonDerivative · entry 7

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · Clay Vanderhook Gift Trust

Disclosed balance after: 52,096

SEC source: 0001843104-26-000012 · wk-form4_1781135953.xml · nonDerivative · entry 6

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · Carter Vanderhook Gift Trust

Disclosed balance after: 52,096

SEC source: 0001843104-26-000012 · wk-form4_1781135953.xml · nonDerivative · entry 5

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · Hayden Vanderhook Gift Trust

Disclosed balance after: 52,096

SEC source: 0001843104-26-000012 · wk-form4_1781135953.xml · nonDerivative · entry 4

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · By GRAT

Disclosed balance after: 0

F1 · balance_after: In addition to the gift transactions reported herein, reflects annuity payments by the GRATs to the Reporting Person pursuant to the terms of the GRAT, which annuity payments were exempt from reporting pursuant to Rule 16a-13.

F5 · ownership.nature: Securities held by the Colbie Vanderhook 2024 grantor retained annuity trust.

SEC source: 0001843104-26-000012 · wk-form4_1781135953.xml · nonDerivative · entry 3

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · By GRAT

Disclosed balance after: 0

F1 · balance_after: In addition to the gift transactions reported herein, reflects annuity payments by the GRATs to the Reporting Person pursuant to the terms of the GRAT, which annuity payments were exempt from reporting pursuant to Rule 16a-13.

F4 · ownership.nature: Securities held by the Clay Vanderhook 2024 grantor retained annuity trust.

SEC source: 0001843104-26-000012 · wk-form4_1781135953.xml · nonDerivative · entry 2

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · By GRAT

Disclosed balance after: 0

F1 · balance_after: In addition to the gift transactions reported herein, reflects annuity payments by the GRATs to the Reporting Person pursuant to the terms of the GRAT, which annuity payments were exempt from reporting pursuant to Rule 16a-13.

F3 · ownership.nature: Securities held by the Carter Vanderhook 2024 grantor retained annuity trust.

SEC source: 0001843104-26-000012 · wk-form4_1781135953.xml · nonDerivative · entry 1

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: No plan indicated

Ownership: Indirect · By GRAT

Disclosed balance after: 0

F1 · balance_after: In addition to the gift transactions reported herein, reflects annuity payments by the GRATs to the Reporting Person pursuant to the terms of the GRAT, which annuity payments were exempt from reporting pursuant to Rule 16a-13.

F2 · ownership.nature: Securities held by the Hayden Vanderhook 2024 grantor retained annuity trust.

SEC source: 0001843104-26-000010 · wk-form4_1779413712.xml · nonDerivative · entry 5

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 0

F4 · kind: Shares sold pursuant to a 10b5-1 plan adopted by Capital V LLC on March 18, 2025, as amended on September 17, 2025.

F7 · price: The price reported in Column 4 is a weighted average price, based on the Reporting Person's pro rata portion of a total of 7,500 shares of Class A Common Stock sold on behalf of Capital V LLC. These shares were sold in multiple transactions at prices ranging from $10.53 to $11.04. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000010 · wk-form4_1779413712.xml · nonDerivative · entry 4

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 2,500

F4 · kind: Shares sold pursuant to a 10b5-1 plan adopted by Capital V LLC on March 18, 2025, as amended on September 17, 2025.

F6 · price: The price reported in Column 4 is a weighted average price, based on the Reporting Person's pro rata portion of a total of 15,000 shares of Class A Common Stock sold on behalf of Capital V LLC. These shares were sold in multiple transactions at prices ranging from $10.31 to $10.96. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000010 · wk-form4_1779413712.xml · derivative · entry 6

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 9,094,775

Underlying: Class A Common Stock · 12,500 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: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F1 · price: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F1 · derivative.exercise_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F1 · derivative.expiration_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000010 · wk-form4_1779413712.xml · nonDerivative · entry 3

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 7,500

F4 · kind: Shares sold pursuant to a 10b5-1 plan adopted by Capital V LLC on March 18, 2025, as amended on September 17, 2025.

F5 · price: The price reported in Column 4 is a weighted average price, based on the Reporting Person's pro rata portion of a total of 15,000 shares of Class A Common Stock sold on behalf of Capital V LLC. These shares were sold in multiple transactions at prices ranging from $10.565 to $11.20. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000010 · wk-form4_1779413712.xml · nonDerivative · entry 2

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 9,094,775

F3 · kind: Reflects the cancellation for no consideration of a number of shares of Class B common stock of the Issuer in connection with the redemption by Capital V LLC of an equal number of Class B Units for Class A common stock.

F3 · price: Reflects the cancellation for no consideration of a number of shares of Class B common stock of the Issuer in connection with the redemption by Capital V LLC of an equal number of Class B Units for Class A common stock.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000010 · wk-form4_1779413712.xml · nonDerivative · entry 1

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 12,500

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 · kind: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F1 · price: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000009 · wk-form4_1776902277.xml · nonDerivative · entry 5

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 0

F4 · kind: Shares sold pursuant to a 10b5-1 plan adopted by Capital V LLC on March 18, 2025, as amended on September 17, 2025.

F7 · price: The price reported in Column 4 is a weighted average price, based on the Reporting Person's pro rata portion of a total of 8,389 shares of Class A Common Stock sold on behalf of Capital V LLC. These shares were sold in multiple transactions at prices ranging from $10.395 to $10.94. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000009 · wk-form4_1776902277.xml · nonDerivative · entry 4

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 2,796

F4 · kind: Shares sold pursuant to a 10b5-1 plan adopted by Capital V LLC on March 18, 2025, as amended on September 17, 2025.

F6 · price: The price reported in Column 4 is a weighted average price, based on the Reporting Person's pro rata portion of a total of 14,111 shares of Class A Common Stock sold on behalf of Capital V LLC. These shares were sold in multiple transactions at prices ranging from $10.64 to $11.46. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000009 · wk-form4_1776902277.xml · derivative · entry 6

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 9,107,275

Underlying: Class A Common Stock · 12,500 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: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F1 · price: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F1 · derivative.exercise_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F1 · derivative.expiration_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000009 · wk-form4_1776902277.xml · nonDerivative · entry 3

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 7,500

F4 · kind: Shares sold pursuant to a 10b5-1 plan adopted by Capital V LLC on March 18, 2025, as amended on September 17, 2025.

F5 · price: The price reported in Column 4 is a weighted average price, based on the Reporting Person's pro rata portion of a total of 15,000 shares of Class A Common Stock sold on behalf of Capital V LLC. These shares were sold in multiple transactions at prices ranging from $11.00 to $11.40. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000009 · wk-form4_1776902277.xml · nonDerivative · entry 2

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 9,107,275

F3 · kind: Reflects the cancellation for no consideration of a number of shares of Class B common stock of the Issuer in connection with the redemption by Capital V LLC of an equal number of Class B Units for Class A common stock.

F3 · price: Reflects the cancellation for no consideration of a number of shares of Class B common stock of the Issuer in connection with the redemption by Capital V LLC of an equal number of Class B Units for Class A common stock.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000009 · wk-form4_1776902277.xml · nonDerivative · entry 1

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 12,500

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 · kind: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F1 · price: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001828791-26-000023 · wk-form4_1773965901.xml · nonDerivative · entry 5

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 0

F4 · kind: Shares sold pursuant to a 10b5-1 plan adopted by Capital V LLC on March 18, 2025, as amended on September 17, 2025.

F7 · price: The price reported in Column 4 is a weighted average price, based on the Reporting Person's pro rata portion of a total of 8,760 shares of Class A Common Stock sold on behalf of Capital V LLC. These shares were sold in multiple transactions at prices ranging from $11.10 to $11.855. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001828791-26-000023 · wk-form4_1773965901.xml · nonDerivative · entry 4

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 2,920

F4 · kind: Shares sold pursuant to a 10b5-1 plan adopted by Capital V LLC on March 18, 2025, as amended on September 17, 2025.

F6 · price: The price reported in Column 4 is a weighted average price, based on the Reporting Person's pro rata portion of a total of 15,000 shares of Class A Common Stock sold on behalf of Capital V LLC. These shares were sold in multiple transactions at prices ranging from $11.675 to $12.46. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001828791-26-000023 · wk-form4_1773965901.xml · derivative · entry 6

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 9,119,775

Underlying: Class A Common Stock · 12,500 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: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F1 · price: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F1 · derivative.exercise_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F1 · derivative.expiration_date: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001828791-26-000023 · wk-form4_1773965901.xml · nonDerivative · entry 3

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 7,920

F4 · kind: Shares sold pursuant to a 10b5-1 plan adopted by Capital V LLC on March 18, 2025, as amended on September 17, 2025.

F5 · price: The price reported in Column 4 is a weighted average price, based on the Reporting Person's pro rata portion of a total of 15,000 shares of Class A Common Stock sold on behalf of Capital V LLC. These shares were sold in multiple transactions at prices ranging from $11.59 to $12.23. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001828791-26-000023 · wk-form4_1773965901.xml · nonDerivative · entry 2

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 9,119,775

F3 · kind: Reflects the cancellation for no consideration of a number of shares of Class B common stock of the Issuer in connection with the redemption by Capital V LLC of an equal number of Class B Units for Class A common stock.

F3 · price: Reflects the cancellation for no consideration of a number of shares of Class B common stock of the Issuer in connection with the redemption by Capital V LLC of an equal number of Class B Units for Class A common stock.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001828791-26-000023 · wk-form4_1773965901.xml · nonDerivative · entry 1

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 12,920

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 · kind: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F1 · price: The Class B Units of Viant Technology LLC ("Class B Units") are exchangeable, at the holder's option, on a one-for-one basis into shares of Class A common stock of the Issuer. Upon exchange of a Class B Unit, the corresponding share of Class B common stock will be automatically cancelled.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.

SEC source: 0001843104-26-000006 · wk-form4_1773354876.xml · nonDerivative · entry 1

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 303,005

F1 · shares: Represents shares repurchased by the Issuer from the Reporting Person in the amount of estimated taxes to be paid by the Reporting Person in connection with the vesting of 82,866 restricted stock units on March 10, 2026.

SEC source: 0001843104-26-000004 · wk-form4_1771552372.xml · nonDerivative · entry 5

Vanderhook Christopher · CIK 0001843104 · Director · Chief Operating Officer · 10% owner

10b5-1 filing: Plan reported

Ownership: Indirect · By Capital V LLC

Disclosed balance after: 420

F4 · kind: Shares sold pursuant to a 10b5-1 plan adopted by Capital V LLC on March 18, 2025, as amended on September 17, 2025.

F7 · price: The price reported in Column 4 is a weighted average price, based on the Reporting Person's pro rata portion of a total of 9,836 shares of Class A Common Stock sold on behalf of Capital V LLC. These shares were sold in multiple transactions at prices ranging from $9.02 to $9.295. The Reporting Person undertakes to provide the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The Reporting Person holds a one-third interest in Capital V LLC and may therefore be deemed to have an indirect pecuniary interest in one-third of Capital V LLC's total holdings.