WGS

SEC source: 0001689575-26-000028 · form4-06182026_080658.xml · nonDerivative · entry 4

Stueland Katherine · CIK 0001689575 · Director · CHIEF EXECUTIVE OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 104,372

F2 · kind: The sale reported on this Form 4 represents shares sold by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of RSUs. The sale was to satisfy tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary transaction by the Reporting Person.

F5 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $61.44 to $61.69 per share, inclusive.

F6 · balance_after: Following the reported sale undertaken to satisfy tax withholding liabilities, in addition to the 104,372 shares of Class A Common Stock beneficially owned by the Reporting Person, the Reporting Person held RSUs representing contingent rights to receive up to an aggregate 305,525 shares of the Issuer's Class A Common Stock and options to purchase up to an aggregate 107,610 shares of Class A Common Stock, which RSUs and options vest according to their respective terms.

SEC source: 0001689575-26-000028 · form4-06182026_080658.xml · nonDerivative · entry 3

Stueland Katherine · CIK 0001689575 · Director · CHIEF EXECUTIVE OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 106,801

F2 · kind: The sale reported on this Form 4 represents shares sold by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of RSUs. The sale was to satisfy tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary transaction by the Reporting Person.

F4 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $60.40 to $61.35 per share, inclusive.

SEC source: 0001689575-26-000028 · form4-06182026_080658.xml · nonDerivative · entry 2

Stueland Katherine · CIK 0001689575 · Director · CHIEF EXECUTIVE OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 112,733

F2 · kind: The sale reported on this Form 4 represents shares sold by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of RSUs. The sale was to satisfy tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary transaction by the Reporting Person.

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $59.26 to $60.24 per share, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote and in footnotes 4 and 5 of this Form 4.

SEC source: 0001689575-26-000028 · form4-06182026_080658.xml · nonDerivative · entry 1

Stueland Katherine · CIK 0001689575 · Director · CHIEF EXECUTIVE OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 114,873

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: Each restricted stock unit ("RSU") represents a contingent right to receive 1 share of the Issuer's Class A Common Stock upon settlement for no consideration.

SEC source: 0001944119-26-000029 · form4-06112026_080641.xml · derivative · entry 3

Feeley Kevin · CIK 0001944119 · CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 4,925

Underlying: Class A Common Stock · 2,462 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: Each restricted stock unit ("RSU") represents a contingent right to receive 1 share of the Issuer's Class A Common Stock upon settlement for no consideration.

F4 · derivative.exercise_date: 6.25% of the total award vested or vests quarterly, subject to the Reporting Person's continued service to the Issuer on each vesting date, and with the first tranche vested on March 9, 2023. These RSUs do not have an expiration date; they either vest or are cancelled prior to the vesting date.

F4 · derivative.expiration_date: 6.25% of the total award vested or vests quarterly, subject to the Reporting Person's continued service to the Issuer on each vesting date, and with the first tranche vested on March 9, 2023. These RSUs do not have an expiration date; they either vest or are cancelled prior to the vesting date.

SEC source: 0001944119-26-000029 · form4-06112026_080641.xml · nonDerivative · entry 2

Feeley Kevin · CIK 0001944119 · CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 36,486

F2 · kind: The sale reported on this Form 4 represents shares sold by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of RSUs. The sale was to satisfy tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary transaction by the Reporting Person.

F3 · balance_after: Following the reported sale undertaken to satisfy tax withholding liabilities, in addition to the 36,486 shares of Class A Common Stock beneficially owned by the Reporting Person, the Reporting Person beneficially owned RSUs representing contingent rights to receive up to an aggregate of 89,240 shares of Class A Common Stock and options to purchase up to an aggregate of 25,906 shares of Class A Common Stock, which RSUs and options vest according to their respective terms.

SEC source: 0001944119-26-000029 · form4-06112026_080641.xml · nonDerivative · entry 1

Feeley Kevin · CIK 0001944119 · CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 37,752

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: Each restricted stock unit ("RSU") represents a contingent right to receive 1 share of the Issuer's Class A Common Stock upon settlement for no consideration.

SEC source: 0001689575-26-000026 · form4-06112026_080609.xml · derivative · entry 3

Stueland Katherine · CIK 0001689575 · Director · CHIEF EXECUTIVE OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 13,094

Underlying: Class A Common Stock · 6,546 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: Each restricted stock unit ("RSU") represents a contingent right to receive 1 share of the Issuer's Class A Common Stock upon settlement for no consideration.

F4 · derivative.exercise_date: 6.25% of the total award vested or vests quarterly, subject to the Reporting Person's continued service to the Issuer on each vesting date, and with the first tranche vested on March 9, 2023. These RSUs do not have an expiration date; they either vest or are cancelled prior to the vesting date.

F4 · derivative.expiration_date: 6.25% of the total award vested or vests quarterly, subject to the Reporting Person's continued service to the Issuer on each vesting date, and with the first tranche vested on March 9, 2023. These RSUs do not have an expiration date; they either vest or are cancelled prior to the vesting date.

SEC source: 0001689575-26-000026 · form4-06112026_080609.xml · nonDerivative · entry 2

Stueland Katherine · CIK 0001689575 · Director · CHIEF EXECUTIVE OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 96,123

F2 · kind: The sale reported on this Form 4 represents shares sold by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of RSUs. The sale was to satisfy tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary transaction by the Reporting Person.

F3 · balance_after: Following the reported sale undertaken to satisfy tax withholding liabilities, in addition to the 96,123 shares of Class A Common Stock beneficially owned by the Reporting Person, the Reporting Person beneficially owned RSUs representing contingent rights to receive up to an aggregate of 324,275 shares of Class A Common Stock and options to purchase up to an aggregate of 107,610 shares of Class A Common Stock, which RSUs and options vest according to their respective terms.

SEC source: 0001689575-26-000026 · form4-06112026_080609.xml · nonDerivative · entry 1

Stueland Katherine · CIK 0001689575 · Director · CHIEF EXECUTIVE OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 99,762

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: Each restricted stock unit ("RSU") represents a contingent right to receive 1 share of the Issuer's Class A Common Stock upon settlement for no consideration.

SEC source: 0000919574-26-003907 · ownership.xml · nonDerivative · entry 2

Casdin Capital, LLC · CIK 0001534261 · Director · 10% owner

Casdin Eli · CIK 0001534264 · Director · 10% owner

Casdin Partners Master Fund, L.P. · CIK 0001534265 · Director · 10% owner

Casdin Partners GP, LLC · CIK 0001534260 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 3,707,164

F1 · ownership.nature: The securities are owned directly by the Casdin Partners Master Fund, L.P. (the "Master Fund") and may be deemed to be indirectly beneficially owned by (i) Casdin Capital, LLC, the investment adviser to the Master Fund ("Casdin"), (ii) Casdin Partners GP, LLC, the general partner of the Master Fund (the "GP"), and (iii) Eli Casdin, the managing member of Casdin and the GP.

SEC source: 0000919574-26-003907 · ownership.xml · nonDerivative · entry 1

Casdin Capital, LLC · CIK 0001534261 · Director · 10% owner

Casdin Eli · CIK 0001534264 · Director · 10% owner

Casdin Partners Master Fund, L.P. · CIK 0001534265 · Director · 10% owner

Casdin Partners GP, LLC · CIK 0001534260 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 3,657,164

F1 · ownership.nature: The securities are owned directly by the Casdin Partners Master Fund, L.P. (the "Master Fund") and may be deemed to be indirectly beneficially owned by (i) Casdin Capital, LLC, the investment adviser to the Master Fund ("Casdin"), (ii) Casdin Partners GP, LLC, the general partner of the Master Fund (the "GP"), and (iii) Eli Casdin, the managing member of Casdin and the GP.

SEC source: 0001944119-26-000027 · form4-06032026_080638.xml · derivative · entry 3

Feeley Kevin · CIK 0001944119 · CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 717

Underlying: Class A Common Stock · 717 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: Each restricted stock unit ("RSU") represents a contingent right to receive 1 share of the Issuer's Class A Common Stock upon settlement for no consideration.

F4 · derivative.exercise_date: 6.25% of the total award vested or vests quarterly, subject to the Reporting Person's continued service to the Issuer on each vesting date, and with the first tranche vested on December 1, 2022. These RSUs do not have an expiration date; they either vest or are cancelled prior to the vesting date.

F4 · derivative.expiration_date: 6.25% of the total award vested or vests quarterly, subject to the Reporting Person's continued service to the Issuer on each vesting date, and with the first tranche vested on December 1, 2022. These RSUs do not have an expiration date; they either vest or are cancelled prior to the vesting date.

SEC source: 0001944119-26-000027 · form4-06032026_080638.xml · nonDerivative · entry 2

Feeley Kevin · CIK 0001944119 · CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 35,290

F2 · kind: The sale reported on this Form 4 represents shares sold by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of RSUs. The sale was to satisfy tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary transaction by the Reporting Person.

F3 · balance_after: Following the reported sale undertaken to satisfy tax withholding liabilities, in addition to the 35,290 shares of Class A Common Stock beneficially owned by the Reporting Person, the Reporting Person beneficially owned RSUs representing contingent rights to receive up to an aggregate 91,702 shares of Class A Common Stock and options to purchase up to an aggregate 25,906 shares of Class A Common Stock, which RSUs and options vest according to their respective terms.

SEC source: 0001944119-26-000027 · form4-06032026_080638.xml · nonDerivative · entry 1

Feeley Kevin · CIK 0001944119 · CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 35,659

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: Each restricted stock unit ("RSU") represents a contingent right to receive 1 share of the Issuer's Class A Common Stock upon settlement for no consideration.

SEC source: 0000919574-26-003627 · ownership.xml · nonDerivative · entry 3

Casdin Capital, LLC · CIK 0001534261 · Director · 10% owner

Casdin Eli · CIK 0001534264 · Director · 10% owner

Casdin Partners Master Fund, L.P. · CIK 0001534265 · Director · 10% owner

Casdin Partners GP, LLC · CIK 0001534260 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 3,507,164

F4 · price: The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $43.6287 to $44.3384. The Reporting Persons undertake to provide to 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 bought at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The securities are owned directly by the Casdin Partners Master Fund, L.P. (the "Master Fund") and may be deemed to be indirectly beneficially owned by (i) Casdin Capital, LLC, the investment adviser to the Master Fund ("Casdin"), (ii) Casdin Partners GP, LLC, the general partner of the Master Fund (the "GP"), and (iii) Eli Casdin, the managing member of Casdin and the GP.

SEC source: 0000919574-26-003627 · ownership.xml · nonDerivative · entry 2

Casdin Capital, LLC · CIK 0001534261 · Director · 10% owner

Casdin Eli · CIK 0001534264 · Director · 10% owner

Casdin Partners Master Fund, L.P. · CIK 0001534265 · Director · 10% owner

Casdin Partners GP, LLC · CIK 0001534260 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 3,367,164

F3 · price: The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $42.1118 to $42.6898. The Reporting Persons undertake to provide to 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 bought at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The securities are owned directly by the Casdin Partners Master Fund, L.P. (the "Master Fund") and may be deemed to be indirectly beneficially owned by (i) Casdin Capital, LLC, the investment adviser to the Master Fund ("Casdin"), (ii) Casdin Partners GP, LLC, the general partner of the Master Fund (the "GP"), and (iii) Eli Casdin, the managing member of Casdin and the GP.

SEC source: 0000919574-26-003627 · ownership.xml · nonDerivative · entry 1

Casdin Capital, LLC · CIK 0001534261 · Director · 10% owner

Casdin Eli · CIK 0001534264 · Director · 10% owner

Casdin Partners Master Fund, L.P. · CIK 0001534265 · Director · 10% owner

Casdin Partners GP, LLC · CIK 0001534260 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnote

Disclosed balance after: 3,182,164

F1 · price: The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $42.4573 to $42.9153. The Reporting Persons undertake to provide to 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 bought at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The securities are owned directly by the Casdin Partners Master Fund, L.P. (the "Master Fund") and may be deemed to be indirectly beneficially owned by (i) Casdin Capital, LLC, the investment adviser to the Master Fund ("Casdin"), (ii) Casdin Partners GP, LLC, the general partner of the Master Fund (the "GP"), and (iii) Eli Casdin, the managing member of Casdin and the GP.

SEC source: 0001011438-26-000351 · form4.xml · nonDerivative · entry 6

Meister Keith A. · CIK 0001307631 · Director · 10% owner

Corvex Management LP · CIK 0001535472 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnotes

Disclosed balance after: 4,784,570

F8 · price: The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $39.78 to $40.60.

F2 · ownership.nature: Investment funds advised by Corvex Management LP ("Corvex") are the direct holders of 4,784,570 shares of the Class A Common Stock, par value $0.0001 per share ("Class A Common Stock") of GeneDX Holdings Corp. (the "Issuer") reported herein. Mr. Meister may be deemed to indirectly beneficially own these shares by virtue of Mr. Meister's control of the general partner of Corvex.

F3 · ownership.nature: For the purposes of this filing, each of Corvex and Mr. Meister disclaims beneficial ownership of the reported securities except to the extent of his or its pecuniary interest therein. This filing shall not be deemed an admission that Corvex or Mr. Meister is the beneficial owner of any of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise.

SEC source: 0001011438-26-000351 · form4.xml · nonDerivative · entry 5

Meister Keith A. · CIK 0001307631 · Director · 10% owner

Corvex Management LP · CIK 0001535472 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnotes

Disclosed balance after: 4,765,705

F7 · price: The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $37.78 to $38.77.

F2 · ownership.nature: Investment funds advised by Corvex Management LP ("Corvex") are the direct holders of 4,784,570 shares of the Class A Common Stock, par value $0.0001 per share ("Class A Common Stock") of GeneDX Holdings Corp. (the "Issuer") reported herein. Mr. Meister may be deemed to indirectly beneficially own these shares by virtue of Mr. Meister's control of the general partner of Corvex.

F3 · ownership.nature: For the purposes of this filing, each of Corvex and Mr. Meister disclaims beneficial ownership of the reported securities except to the extent of his or its pecuniary interest therein. This filing shall not be deemed an admission that Corvex or Mr. Meister is the beneficial owner of any of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise.

SEC source: 0001011438-26-000351 · form4.xml · nonDerivative · entry 4

Meister Keith A. · CIK 0001307631 · Director · 10% owner

Corvex Management LP · CIK 0001535472 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnotes

Disclosed balance after: 4,738,297

F6 · price: The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $39.79 to $40.00.

F2 · ownership.nature: Investment funds advised by Corvex Management LP ("Corvex") are the direct holders of 4,784,570 shares of the Class A Common Stock, par value $0.0001 per share ("Class A Common Stock") of GeneDX Holdings Corp. (the "Issuer") reported herein. Mr. Meister may be deemed to indirectly beneficially own these shares by virtue of Mr. Meister's control of the general partner of Corvex.

F3 · ownership.nature: For the purposes of this filing, each of Corvex and Mr. Meister disclaims beneficial ownership of the reported securities except to the extent of his or its pecuniary interest therein. This filing shall not be deemed an admission that Corvex or Mr. Meister is the beneficial owner of any of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise.

SEC source: 0001011438-26-000351 · form4.xml · nonDerivative · entry 3

Meister Keith A. · CIK 0001307631 · Director · 10% owner

Corvex Management LP · CIK 0001535472 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnotes

Disclosed balance after: 4,686,404

F5 · price: The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $38.79 to $39.77.

F2 · ownership.nature: Investment funds advised by Corvex Management LP ("Corvex") are the direct holders of 4,784,570 shares of the Class A Common Stock, par value $0.0001 per share ("Class A Common Stock") of GeneDX Holdings Corp. (the "Issuer") reported herein. Mr. Meister may be deemed to indirectly beneficially own these shares by virtue of Mr. Meister's control of the general partner of Corvex.

F3 · ownership.nature: For the purposes of this filing, each of Corvex and Mr. Meister disclaims beneficial ownership of the reported securities except to the extent of his or its pecuniary interest therein. This filing shall not be deemed an admission that Corvex or Mr. Meister is the beneficial owner of any of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise.

SEC source: 0001011438-26-000351 · form4.xml · nonDerivative · entry 2

Meister Keith A. · CIK 0001307631 · Director · 10% owner

Corvex Management LP · CIK 0001535472 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnotes

Disclosed balance after: 4,598,297

F4 · price: The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $39.21 to $39.80.

F2 · ownership.nature: Investment funds advised by Corvex Management LP ("Corvex") are the direct holders of 4,784,570 shares of the Class A Common Stock, par value $0.0001 per share ("Class A Common Stock") of GeneDX Holdings Corp. (the "Issuer") reported herein. Mr. Meister may be deemed to indirectly beneficially own these shares by virtue of Mr. Meister's control of the general partner of Corvex.

F3 · ownership.nature: For the purposes of this filing, each of Corvex and Mr. Meister disclaims beneficial ownership of the reported securities except to the extent of his or its pecuniary interest therein. This filing shall not be deemed an admission that Corvex or Mr. Meister is the beneficial owner of any of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise.

SEC source: 0001011438-26-000351 · form4.xml · nonDerivative · entry 1

Meister Keith A. · CIK 0001307631 · Director · 10% owner

Corvex Management LP · CIK 0001535472 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnotes

Disclosed balance after: 4,527,371

F1 · price: The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $38.21 to $39.20. The Reporting Persons undertake to provide to 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 bought at each separate price within the ranges set forth in footnotes (1), (4), (5), (6), (7) and (8) to this Form 4.

F2 · ownership.nature: Investment funds advised by Corvex Management LP ("Corvex") are the direct holders of 4,784,570 shares of the Class A Common Stock, par value $0.0001 per share ("Class A Common Stock") of GeneDX Holdings Corp. (the "Issuer") reported herein. Mr. Meister may be deemed to indirectly beneficially own these shares by virtue of Mr. Meister's control of the general partner of Corvex.

F3 · ownership.nature: For the purposes of this filing, each of Corvex and Mr. Meister disclaims beneficial ownership of the reported securities except to the extent of his or its pecuniary interest therein. This filing shall not be deemed an admission that Corvex or Mr. Meister is the beneficial owner of any of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise.

SEC source: 0001011438-26-000276 · form4.xml · nonDerivative · entry 13

Meister Keith A. · CIK 0001307631 · Director · 10% owner

Corvex Management LP · CIK 0001535472 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnotes

Disclosed balance after: 4,433,297

F15 · price: The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $40.22 to $40.41.

F2 · ownership.nature: Investment funds advised by Corvex Management LP ("Corvex") are the direct holders of 4,433,297 shares of the Class A Common Stock, par value $0.0001 per share ("Class A Common Stock") of GeneDX Holdings Corp. (the "Issuer") reported herein. Mr. Meister may be deemed to indirectly beneficially own these shares by virtue of Mr. Meister's control of the general partner of Corvex.

F3 · ownership.nature: For the purposes of this filing, each of Corvex and Mr. Meister disclaims beneficial ownership of the reported securities except to the extent of his or its pecuniary interest therein. This filing shall not be deemed an admission that Corvex or Mr. Meister is the beneficial owner of any of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise.

SEC source: 0001011438-26-000276 · form4.xml · nonDerivative · entry 12

Meister Keith A. · CIK 0001307631 · Director · 10% owner

Corvex Management LP · CIK 0001535472 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnotes

Disclosed balance after: 4,432,765

F14 · price: The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $39.22 to $40.21.

F2 · ownership.nature: Investment funds advised by Corvex Management LP ("Corvex") are the direct holders of 4,433,297 shares of the Class A Common Stock, par value $0.0001 per share ("Class A Common Stock") of GeneDX Holdings Corp. (the "Issuer") reported herein. Mr. Meister may be deemed to indirectly beneficially own these shares by virtue of Mr. Meister's control of the general partner of Corvex.

F3 · ownership.nature: For the purposes of this filing, each of Corvex and Mr. Meister disclaims beneficial ownership of the reported securities except to the extent of his or its pecuniary interest therein. This filing shall not be deemed an admission that Corvex or Mr. Meister is the beneficial owner of any of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise.

SEC source: 0001011438-26-000276 · form4.xml · nonDerivative · entry 11

Meister Keith A. · CIK 0001307631 · Director · 10% owner

Corvex Management LP · CIK 0001535472 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnotes

Disclosed balance after: 4,180,031

F13 · price: The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $38.22 to $39.21.

F2 · ownership.nature: Investment funds advised by Corvex Management LP ("Corvex") are the direct holders of 4,433,297 shares of the Class A Common Stock, par value $0.0001 per share ("Class A Common Stock") of GeneDX Holdings Corp. (the "Issuer") reported herein. Mr. Meister may be deemed to indirectly beneficially own these shares by virtue of Mr. Meister's control of the general partner of Corvex.

F3 · ownership.nature: For the purposes of this filing, each of Corvex and Mr. Meister disclaims beneficial ownership of the reported securities except to the extent of his or its pecuniary interest therein. This filing shall not be deemed an admission that Corvex or Mr. Meister is the beneficial owner of any of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise.

SEC source: 0000919574-26-002845 · ownership.xml · derivative · entry 3

Casdin Capital, LLC · CIK 0001534261 · Director · 10% owner

Casdin Eli · CIK 0001534264 · Director · 10% owner

Casdin Partners Master Fund, L.P. · CIK 0001534265 · Director · 10% owner

Casdin Partners GP, LLC · CIK 0001534260 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 850,000

Underlying: Class A Common Stock · 50,000 shares

Expires not disclosed

F4 · derivative.exercise_price: The Master Fund has entered into certain cash-settled swap agreements (the "Swap Agreements"), which represent economic exposure to an aggregate of 50,000 notional shares of the Issuer's Class A Common Stock, at a price of $39.6602 per share. The Swap Agreements provide the Master Fund with economic results that are comparable to the economic results of ownership but do not provide it with the power to vote or direct the voting or dispose of or direct the disposition of the securities that are referenced by the Swap Agreements.

F4 · price: The Master Fund has entered into certain cash-settled swap agreements (the "Swap Agreements"), which represent economic exposure to an aggregate of 50,000 notional shares of the Issuer's Class A Common Stock, at a price of $39.6602 per share. The Swap Agreements provide the Master Fund with economic results that are comparable to the economic results of ownership but do not provide it with the power to vote or direct the voting or dispose of or direct the disposition of the securities that are referenced by the Swap Agreements.

F4 · derivative.exercise_date: The Master Fund has entered into certain cash-settled swap agreements (the "Swap Agreements"), which represent economic exposure to an aggregate of 50,000 notional shares of the Issuer's Class A Common Stock, at a price of $39.6602 per share. The Swap Agreements provide the Master Fund with economic results that are comparable to the economic results of ownership but do not provide it with the power to vote or direct the voting or dispose of or direct the disposition of the securities that are referenced by the Swap Agreements.

F4 · derivative.expiration_date: The Master Fund has entered into certain cash-settled swap agreements (the "Swap Agreements"), which represent economic exposure to an aggregate of 50,000 notional shares of the Issuer's Class A Common Stock, at a price of $39.6602 per share. The Swap Agreements provide the Master Fund with economic results that are comparable to the economic results of ownership but do not provide it with the power to vote or direct the voting or dispose of or direct the disposition of the securities that are referenced by the Swap Agreements.

F2 · ownership.nature: The Swap Agreements are owned directly by the Master Fund and may be deemed to be indirectly beneficially owned by (i) Casdin Capital, LLC, the investment adviser to the Master Fund ("Casdin"), (ii) Casdin Partners GP, LLC, the general partner of the Master Fund (the "GP"), and (iii) Eli Casdin, the managing member of Casdin and the GP.

SEC source: 0001011438-26-000276 · form4.xml · nonDerivative · entry 10

Meister Keith A. · CIK 0001307631 · Director · 10% owner

Corvex Management LP · CIK 0001535472 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnotes

Disclosed balance after: 3,933,297

F12 · price: The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $40.95 to $41.50.

F2 · ownership.nature: Investment funds advised by Corvex Management LP ("Corvex") are the direct holders of 4,433,297 shares of the Class A Common Stock, par value $0.0001 per share ("Class A Common Stock") of GeneDX Holdings Corp. (the "Issuer") reported herein. Mr. Meister may be deemed to indirectly beneficially own these shares by virtue of Mr. Meister's control of the general partner of Corvex.

F3 · ownership.nature: For the purposes of this filing, each of Corvex and Mr. Meister disclaims beneficial ownership of the reported securities except to the extent of his or its pecuniary interest therein. This filing shall not be deemed an admission that Corvex or Mr. Meister is the beneficial owner of any of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise.

SEC source: 0001011438-26-000276 · form4.xml · nonDerivative · entry 9

Meister Keith A. · CIK 0001307631 · Director · 10% owner

Corvex Management LP · CIK 0001535472 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnotes

Disclosed balance after: 3,860,193

F11 · price: The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $39.95 to $40.94.

F2 · ownership.nature: Investment funds advised by Corvex Management LP ("Corvex") are the direct holders of 4,433,297 shares of the Class A Common Stock, par value $0.0001 per share ("Class A Common Stock") of GeneDX Holdings Corp. (the "Issuer") reported herein. Mr. Meister may be deemed to indirectly beneficially own these shares by virtue of Mr. Meister's control of the general partner of Corvex.

F3 · ownership.nature: For the purposes of this filing, each of Corvex and Mr. Meister disclaims beneficial ownership of the reported securities except to the extent of his or its pecuniary interest therein. This filing shall not be deemed an admission that Corvex or Mr. Meister is the beneficial owner of any of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise.

SEC source: 0001011438-26-000276 · form4.xml · nonDerivative · entry 8

Meister Keith A. · CIK 0001307631 · Director · 10% owner

Corvex Management LP · CIK 0001535472 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnotes

Disclosed balance after: 3,781,049

F10 · price: The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $38.59 to $38.94.

F2 · ownership.nature: Investment funds advised by Corvex Management LP ("Corvex") are the direct holders of 4,433,297 shares of the Class A Common Stock, par value $0.0001 per share ("Class A Common Stock") of GeneDX Holdings Corp. (the "Issuer") reported herein. Mr. Meister may be deemed to indirectly beneficially own these shares by virtue of Mr. Meister's control of the general partner of Corvex.

F3 · ownership.nature: For the purposes of this filing, each of Corvex and Mr. Meister disclaims beneficial ownership of the reported securities except to the extent of his or its pecuniary interest therein. This filing shall not be deemed an admission that Corvex or Mr. Meister is the beneficial owner of any of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise.

SEC source: 0001011438-26-000276 · form4.xml · nonDerivative · entry 7

Meister Keith A. · CIK 0001307631 · Director · 10% owner

Corvex Management LP · CIK 0001535472 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnotes

Disclosed balance after: 3,777,653

F9 · price: The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $37.59 to $38.58.

F2 · ownership.nature: Investment funds advised by Corvex Management LP ("Corvex") are the direct holders of 4,433,297 shares of the Class A Common Stock, par value $0.0001 per share ("Class A Common Stock") of GeneDX Holdings Corp. (the "Issuer") reported herein. Mr. Meister may be deemed to indirectly beneficially own these shares by virtue of Mr. Meister's control of the general partner of Corvex.

F3 · ownership.nature: For the purposes of this filing, each of Corvex and Mr. Meister disclaims beneficial ownership of the reported securities except to the extent of his or its pecuniary interest therein. This filing shall not be deemed an admission that Corvex or Mr. Meister is the beneficial owner of any of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise.

SEC source: 0000919574-26-002845 · ownership.xml · derivative · entry 2

Casdin Capital, LLC · CIK 0001534261 · Director · 10% owner

Casdin Eli · CIK 0001534264 · Director · 10% owner

Casdin Partners Master Fund, L.P. · CIK 0001534265 · Director · 10% owner

Casdin Partners GP, LLC · CIK 0001534260 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 800,000

Underlying: Class A Common Stock · 300,000 shares

Expires not disclosed

F3 · derivative.exercise_price: The Master Fund has entered into certain cash-settled swap agreements (the "Swap Agreements"), which represent economic exposure to an aggregate of 300,000 notional shares of the Issuer's Class A Common Stock, at a price of $41.0261 per share. The Swap Agreements provide the Master Fund with economic results that are comparable to the economic results of ownership but do not provide it with the power to vote or direct the voting or dispose of or direct the disposition of the securities that are referenced by the Swap Agreements.

F3 · price: The Master Fund has entered into certain cash-settled swap agreements (the "Swap Agreements"), which represent economic exposure to an aggregate of 300,000 notional shares of the Issuer's Class A Common Stock, at a price of $41.0261 per share. The Swap Agreements provide the Master Fund with economic results that are comparable to the economic results of ownership but do not provide it with the power to vote or direct the voting or dispose of or direct the disposition of the securities that are referenced by the Swap Agreements.

F3 · derivative.exercise_date: The Master Fund has entered into certain cash-settled swap agreements (the "Swap Agreements"), which represent economic exposure to an aggregate of 300,000 notional shares of the Issuer's Class A Common Stock, at a price of $41.0261 per share. The Swap Agreements provide the Master Fund with economic results that are comparable to the economic results of ownership but do not provide it with the power to vote or direct the voting or dispose of or direct the disposition of the securities that are referenced by the Swap Agreements.

F3 · derivative.expiration_date: The Master Fund has entered into certain cash-settled swap agreements (the "Swap Agreements"), which represent economic exposure to an aggregate of 300,000 notional shares of the Issuer's Class A Common Stock, at a price of $41.0261 per share. The Swap Agreements provide the Master Fund with economic results that are comparable to the economic results of ownership but do not provide it with the power to vote or direct the voting or dispose of or direct the disposition of the securities that are referenced by the Swap Agreements.

F2 · ownership.nature: The Swap Agreements are owned directly by the Master Fund and may be deemed to be indirectly beneficially owned by (i) Casdin Capital, LLC, the investment adviser to the Master Fund ("Casdin"), (ii) Casdin Partners GP, LLC, the general partner of the Master Fund (the "GP"), and (iii) Eli Casdin, the managing member of Casdin and the GP.

SEC source: 0001011438-26-000276 · form4.xml · nonDerivative · entry 6

Meister Keith A. · CIK 0001307631 · Director · 10% owner

Corvex Management LP · CIK 0001535472 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnotes

Disclosed balance after: 3,761,908

F8 · price: The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $40.05 to $40.66.

F2 · ownership.nature: Investment funds advised by Corvex Management LP ("Corvex") are the direct holders of 4,433,297 shares of the Class A Common Stock, par value $0.0001 per share ("Class A Common Stock") of GeneDX Holdings Corp. (the "Issuer") reported herein. Mr. Meister may be deemed to indirectly beneficially own these shares by virtue of Mr. Meister's control of the general partner of Corvex.

F3 · ownership.nature: For the purposes of this filing, each of Corvex and Mr. Meister disclaims beneficial ownership of the reported securities except to the extent of his or its pecuniary interest therein. This filing shall not be deemed an admission that Corvex or Mr. Meister is the beneficial owner of any of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise.

SEC source: 0001011438-26-000276 · form4.xml · nonDerivative · entry 5

Meister Keith A. · CIK 0001307631 · Director · 10% owner

Corvex Management LP · CIK 0001535472 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnotes

Disclosed balance after: 3,705,278

F7 · price: The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $39.05 to $40.04.

F2 · ownership.nature: Investment funds advised by Corvex Management LP ("Corvex") are the direct holders of 4,433,297 shares of the Class A Common Stock, par value $0.0001 per share ("Class A Common Stock") of GeneDX Holdings Corp. (the "Issuer") reported herein. Mr. Meister may be deemed to indirectly beneficially own these shares by virtue of Mr. Meister's control of the general partner of Corvex.

F3 · ownership.nature: For the purposes of this filing, each of Corvex and Mr. Meister disclaims beneficial ownership of the reported securities except to the extent of his or its pecuniary interest therein. This filing shall not be deemed an admission that Corvex or Mr. Meister is the beneficial owner of any of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise.

SEC source: 0001011438-26-000276 · form4.xml · nonDerivative · entry 4

Meister Keith A. · CIK 0001307631 · Director · 10% owner

Corvex Management LP · CIK 0001535472 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnotes

Disclosed balance after: 3,610,922

F6 · price: The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $38.05 to $39.04.

F2 · ownership.nature: Investment funds advised by Corvex Management LP ("Corvex") are the direct holders of 4,433,297 shares of the Class A Common Stock, par value $0.0001 per share ("Class A Common Stock") of GeneDX Holdings Corp. (the "Issuer") reported herein. Mr. Meister may be deemed to indirectly beneficially own these shares by virtue of Mr. Meister's control of the general partner of Corvex.

F3 · ownership.nature: For the purposes of this filing, each of Corvex and Mr. Meister disclaims beneficial ownership of the reported securities except to the extent of his or its pecuniary interest therein. This filing shall not be deemed an admission that Corvex or Mr. Meister is the beneficial owner of any of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise.

SEC source: 0001011438-26-000276 · form4.xml · nonDerivative · entry 3

Meister Keith A. · CIK 0001307631 · Director · 10% owner

Corvex Management LP · CIK 0001535472 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnotes

Disclosed balance after: 3,494,510

F5 · price: The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $37.05 to $38.04.

F2 · ownership.nature: Investment funds advised by Corvex Management LP ("Corvex") are the direct holders of 4,433,297 shares of the Class A Common Stock, par value $0.0001 per share ("Class A Common Stock") of GeneDX Holdings Corp. (the "Issuer") reported herein. Mr. Meister may be deemed to indirectly beneficially own these shares by virtue of Mr. Meister's control of the general partner of Corvex.

F3 · ownership.nature: For the purposes of this filing, each of Corvex and Mr. Meister disclaims beneficial ownership of the reported securities except to the extent of his or its pecuniary interest therein. This filing shall not be deemed an admission that Corvex or Mr. Meister is the beneficial owner of any of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise.

SEC source: 0001011438-26-000276 · form4.xml · nonDerivative · entry 2

Meister Keith A. · CIK 0001307631 · Director · 10% owner

Corvex Management LP · CIK 0001535472 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnotes

Disclosed balance after: 3,371,117

F4 · price: The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $35.97 to $36.84.

F2 · ownership.nature: Investment funds advised by Corvex Management LP ("Corvex") are the direct holders of 4,433,297 shares of the Class A Common Stock, par value $0.0001 per share ("Class A Common Stock") of GeneDX Holdings Corp. (the "Issuer") reported herein. Mr. Meister may be deemed to indirectly beneficially own these shares by virtue of Mr. Meister's control of the general partner of Corvex.

F3 · ownership.nature: For the purposes of this filing, each of Corvex and Mr. Meister disclaims beneficial ownership of the reported securities except to the extent of his or its pecuniary interest therein. This filing shall not be deemed an admission that Corvex or Mr. Meister is the beneficial owner of any of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise.

SEC source: 0001011438-26-000276 · form4.xml · nonDerivative · entry 1

Meister Keith A. · CIK 0001307631 · Director · 10% owner

Corvex Management LP · CIK 0001535472 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See footnotes

Disclosed balance after: 3,356,331

F1 · price: The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $34.97 to $35.94. The Reporting Persons undertake to provide to 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 bought at each separate price within the ranges set forth in footnotes (1), (4), (5), (6), (7), (8), (9), (10), (11), (12), (13), (14) and (15) to this Form 4.

F2 · ownership.nature: Investment funds advised by Corvex Management LP ("Corvex") are the direct holders of 4,433,297 shares of the Class A Common Stock, par value $0.0001 per share ("Class A Common Stock") of GeneDX Holdings Corp. (the "Issuer") reported herein. Mr. Meister may be deemed to indirectly beneficially own these shares by virtue of Mr. Meister's control of the general partner of Corvex.

F3 · ownership.nature: For the purposes of this filing, each of Corvex and Mr. Meister disclaims beneficial ownership of the reported securities except to the extent of his or its pecuniary interest therein. This filing shall not be deemed an admission that Corvex or Mr. Meister is the beneficial owner of any of the reported securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise.

SEC source: 0000919574-26-002845 · ownership.xml · derivative · entry 1

Casdin Capital, LLC · CIK 0001534261 · Director · 10% owner

Casdin Eli · CIK 0001534264 · Director · 10% owner

Casdin Partners Master Fund, L.P. · CIK 0001534265 · Director · 10% owner

Casdin Partners GP, LLC · CIK 0001534260 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: No plan indicated

Ownership: Indirect · See Footnote

Disclosed balance after: 500,000

Underlying: Class A Common Stock · 500,000 shares

Expires not disclosed

F1 · derivative.exercise_price: Casdin Partners Master Fund, L.P. (the "Master Fund") has entered into certain cash-settled swap agreements (the "Swap Agreements"), which represent economic exposure to an aggregate of 500,000 notional shares of the Issuer's Class A Common Stock, at a price of $38.1543 per share. The Swap Agreements provide the Master Fund with economic results that are comparable to the economic results of ownership but do not provide it with the power to vote or direct the voting or dispose of or direct the disposition of the securities that are referenced by the Swap Agreements.

F1 · price: Casdin Partners Master Fund, L.P. (the "Master Fund") has entered into certain cash-settled swap agreements (the "Swap Agreements"), which represent economic exposure to an aggregate of 500,000 notional shares of the Issuer's Class A Common Stock, at a price of $38.1543 per share. The Swap Agreements provide the Master Fund with economic results that are comparable to the economic results of ownership but do not provide it with the power to vote or direct the voting or dispose of or direct the disposition of the securities that are referenced by the Swap Agreements.

F1 · derivative.exercise_date: Casdin Partners Master Fund, L.P. (the "Master Fund") has entered into certain cash-settled swap agreements (the "Swap Agreements"), which represent economic exposure to an aggregate of 500,000 notional shares of the Issuer's Class A Common Stock, at a price of $38.1543 per share. The Swap Agreements provide the Master Fund with economic results that are comparable to the economic results of ownership but do not provide it with the power to vote or direct the voting or dispose of or direct the disposition of the securities that are referenced by the Swap Agreements.

F1 · derivative.expiration_date: Casdin Partners Master Fund, L.P. (the "Master Fund") has entered into certain cash-settled swap agreements (the "Swap Agreements"), which represent economic exposure to an aggregate of 500,000 notional shares of the Issuer's Class A Common Stock, at a price of $38.1543 per share. The Swap Agreements provide the Master Fund with economic results that are comparable to the economic results of ownership but do not provide it with the power to vote or direct the voting or dispose of or direct the disposition of the securities that are referenced by the Swap Agreements.

F2 · ownership.nature: The Swap Agreements are owned directly by the Master Fund and may be deemed to be indirectly beneficially owned by (i) Casdin Capital, LLC, the investment adviser to the Master Fund ("Casdin"), (ii) Casdin Partners GP, LLC, the general partner of the Master Fund (the "GP"), and (iii) Eli Casdin, the managing member of Casdin and the GP.

SEC source: 0001944119-26-000024 · form4-05012026_080528.xml · derivative · entry 3

Feeley Kevin · CIK 0001944119 · CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Class A Common Stock · 754 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: Each restricted stock unit ("RSU") represents a contingent right to receive 1 share of the Issuer's Class A Common Stock upon settlement for no consideration.

F5 · derivative.exercise_date: 25% of the total award vested on each of April 29, 2023 and April 29, 2024, and an additional 6.25% of the total award vested or vests thereafter on each quarterly anniversary, subject to the Reporting Person's continued service to the Issuer on each vesting date, with the last tranche vesting on April 29, 2026. These RSUs do not have an expiration date; they either vest or are cancelled prior to the vesting date.

F5 · derivative.expiration_date: 25% of the total award vested on each of April 29, 2023 and April 29, 2024, and an additional 6.25% of the total award vested or vests thereafter on each quarterly anniversary, subject to the Reporting Person's continued service to the Issuer on each vesting date, with the last tranche vesting on April 29, 2026. These RSUs do not have an expiration date; they either vest or are cancelled prior to the vesting date.

SEC source: 0001944119-26-000024 · form4-05012026_080528.xml · nonDerivative · entry 2

Feeley Kevin · CIK 0001944119 · CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 34,942

F2 · kind: The sale reported on this Form 4 represents shares sold by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of RSUs. The sale was to satisfy tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary transaction by the Reporting Person.

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $64.4739 to $65.20 per share, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the U.S. 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.

F4 · balance_after: Following the reported sale undertaken to satisfy tax withholding liabilities, in addition to the 34,942 shares of Class A Common Stock beneficially owned by the Reporting Person, the Reporting Person beneficially owned RSUs representing contingent rights to receive up to an aggregate of 92,419 shares of Class A Common Stock and options to purchase up to an aggregate of 25,906 shares of Class A Common Stock, which RSUs and options vest according to their respective terms.

SEC source: 0001944119-26-000024 · form4-05012026_080528.xml · nonDerivative · entry 1

Feeley Kevin · CIK 0001944119 · CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 35,334

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: Each restricted stock unit ("RSU") represents a contingent right to receive 1 share of the Issuer's Class A Common Stock upon settlement for no consideration.

SEC source: 0001689575-26-000024 · form4-05012026_080508.xml · derivative · entry 4

Stueland Katherine · CIK 0001689575 · Director · CHIEF EXECUTIVE OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Class A Common Stock · 3,874 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: Each restricted stock unit ("RSU") represents a contingent right to receive 1 share of the Issuer's Class A Common Stock upon settlement for no consideration.

F4 · derivative.exercise_date: 25% of the total award vested on each of April 29, 2023 and April 29, 2024, and an additional 6.25% of the total award vested or vests thereafter on each quarterly anniversary, subject to the Reporting Person's continued service to the Issuer on each vesting date, with the last tranche vesting on April 29, 2026. These RSUs do not have an expiration date; they either vest or are cancelled prior to the vesting date.

F4 · derivative.expiration_date: 25% of the total award vested on each of April 29, 2023 and April 29, 2024, and an additional 6.25% of the total award vested or vests thereafter on each quarterly anniversary, subject to the Reporting Person's continued service to the Issuer on each vesting date, with the last tranche vesting on April 29, 2026. These RSUs do not have an expiration date; they either vest or are cancelled prior to the vesting date.

SEC source: 0001689575-26-000024 · form4-05012026_080508.xml · nonDerivative · entry 3

Stueland Katherine · CIK 0001689575 · Director · CHIEF EXECUTIVE OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 93,216

F2 · kind: The sale reported on this Form 4 represents shares sold by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of RSUs. The sale was to satisfy tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary transaction by the Reporting Person.

F3 · balance_after: Following the reported sale undertaken to satisfy tax withholding liabilities, in addition to the 93,216 shares of Class A Common Stock beneficially owned by the Reporting Person, the Reporting Person beneficially owned RSUs representing contingent rights to receive up to an aggregate of 330,821 shares of Class A Common Stock and options to purchase up to an aggregate of 107,610 shares of Class A Common Stock, which RSUs and options vest according to their respective terms.

SEC source: 0001689575-26-000024 · form4-05012026_080508.xml · nonDerivative · entry 2

Stueland Katherine · CIK 0001689575 · Director · CHIEF EXECUTIVE OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 93,234

F2 · kind: The sale reported on this Form 4 represents shares sold by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of RSUs. The sale was to satisfy tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary transaction by the Reporting Person.

SEC source: 0001689575-26-000024 · form4-05012026_080508.xml · nonDerivative · entry 1

Stueland Katherine · CIK 0001689575 · Director · CHIEF EXECUTIVE OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 95,388

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: Each restricted stock unit ("RSU") represents a contingent right to receive 1 share of the Issuer's Class A Common Stock upon settlement for no consideration.

SEC source: 0001944119-26-000021 · form4-03302026_090356.xml · derivative · entry 7

Feeley Kevin · CIK 0001944119 · CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 32,500

Underlying: Class A Common Stock · 16,250 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: Each restricted stock unit ("RSU") represents a contingent right to receive 1 share of the Issuer's Class A Common Stock upon settlement for no consideration.

F9 · derivative.exercise_date: 25% of the total award vested or vests annually, with the first tranche vested on March 26, 2025, subject to the Reporting Person's continued service to the Issuer on each vesting date. These RSUs do not have an expiration date; they either vest or are cancelled prior to the vesting date.

F9 · derivative.expiration_date: 25% of the total award vested or vests annually, with the first tranche vested on March 26, 2025, subject to the Reporting Person's continued service to the Issuer on each vesting date. These RSUs do not have an expiration date; they either vest or are cancelled prior to the vesting date.

SEC source: 0001944119-26-000021 · form4-03302026_090356.xml · nonDerivative · entry 6

Feeley Kevin · CIK 0001944119 · CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 34,580

F2 · kind: The sale reported on this Form 4 represents shares sold by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of RSUs. The sale was to satisfy tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary transaction by the Reporting Person.

F7 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $65.00 to $65.61 per share, inclusive.

F8 · balance_after: Following the reported sale undertaken to satisfy tax withholding liabilities, in addition to the 34,580 shares of Class A Common Stock beneficially owned by the Reporting Person, the Reporting Person held RSUs representing contingent rights to receive up to an aggregate 93,173 shares of the Issuer's Class A Common Stock and options to purchase up to an aggregate 25,906 shares of Class A Common Stock, which RSUs and options vest according to their respective terms.

SEC source: 0001944119-26-000021 · form4-03302026_090356.xml · nonDerivative · entry 5

Feeley Kevin · CIK 0001944119 · CHIEF FINANCIAL OFFICER

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 36,437

F2 · kind: The sale reported on this Form 4 represents shares sold by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of RSUs. The sale was to satisfy tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary transaction by the Reporting Person.

F6 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $63.99 to $64.96 per share, inclusive.