Mahoney Stephen F.

SEC source: 0001193125-26-092036 · ownership.xml · derivative · entry 5

Mahoney Stephen F. · CIK 0001741389 · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 55,071

Underlying: Common Stock · 18,357 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.

F2 · derivative.exercise_price: Each Restricted Stock Unit (RSU) represents a contingent right to receive one share of common stock of the Issuer.

F4 · derivative.exercise_date: The RSUs vest over a four year period, with 25% of the RSUs vesting on each yearly anniversary of the date of grant, March 3, 2025, subject to the Reporting Person's continued service to Issuer through each vesting date.

F4 · derivative.expiration_date: The RSUs vest over a four year period, with 25% of the RSUs vesting on each yearly anniversary of the date of grant, March 3, 2025, subject to the Reporting Person's continued service to Issuer through each vesting date.

SEC source: 0001193125-26-092036 · ownership.xml · nonDerivative · entry 2

Mahoney Stephen F. · CIK 0001741389 · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 33,130

F5 · balance_after: Includes 1,000 shares acquired under Viridian Therapeutics, Inc.'s 2016 Employee Stock Purchase Plan (the "ESPP") on March 17, 2025 in transactions that were exempt under Rule 16b-3(c).

SEC source: 0001193125-26-092036 · ownership.xml · nonDerivative · entry 1

Mahoney Stephen F. · CIK 0001741389 · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 40,757

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.

F2 · price: Each Restricted Stock Unit (RSU) represents a contingent right to receive one share of common stock of the Issuer.

F5 · balance_after: Includes 1,000 shares acquired under Viridian Therapeutics, Inc.'s 2016 Employee Stock Purchase Plan (the "ESPP") on March 17, 2025 in transactions that were exempt under Rule 16b-3(c).

SEC source: 0001193125-26-099007 · ownership.xml · nonDerivative · entry 1

Mahoney Stephen F. · CIK 0001741389 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 33,349

F1 · shares: This amendment corrects the number of shares and price sold to cover taxes on the initial Form 4 filed on March 4, 2026, as well as the resulting total number of shares beneficially owned following all transactions reported in the initial Form 4.

F1 · balance_after: This amendment corrects the number of shares and price sold to cover taxes on the initial Form 4 filed on March 4, 2026, as well as the resulting total number of shares beneficially owned following all transactions reported in the initial Form 4.

SEC source: 0001193125-26-092036 · ownership.xml · derivative · entry 4

Mahoney Stephen F. · CIK 0001741389 · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 111,900

Underlying: Common Stock · 111,900 shares

Expires not disclosed

F2 · derivative.exercise_price: Each Restricted Stock Unit (RSU) represents a contingent right to receive one share of common stock of the Issuer.

F3 · derivative.exercise_date: The RSUs vest over a four year period, with 25% of the RSUs vesting on each yearly anniversary of the date of grant, March 2, 2026, subject to the Reporting Person's continued service to Issuer through each vesting date.

F3 · derivative.expiration_date: The RSUs vest over a four year period, with 25% of the RSUs vesting on each yearly anniversary of the date of grant, March 2, 2026, subject to the Reporting Person's continued service to Issuer through each vesting date.

SEC source: 0001193125-26-092036 · ownership.xml · derivative · entry 3

Mahoney Stephen F. · CIK 0001741389 · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 559,600

Underlying: Common Stock · 559,600 shares

Expires 2036-03-02

F1 · derivative.exercise_date: The option vests and becomes exercisable in 48 equal monthly installments following the date of the grant, subject to the Reporting Person's continued service to Issuer through each vesting date. The date of the grant is March 2, 2026.

SEC source: 0000950170-25-032891 · ownership.xml · derivative · entry 2

Mahoney Stephen F. · CIK 0001741389 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 73,428

Underlying: Common Stock · 73,428 shares

Expires not disclosed

F2 · derivative.exercise_price: Each Restricted Stock Unit (RSU) represents a contingent right to receive one share of common stock of the Issuer.

F3 · derivative.exercise_date: The RSUs vest over a four year period, with 25% of the RSUs vesting on each yearly anniversary of the date of grant, March 3, 2025, subject to the Reporting Person's continued service to Issuer through each vesting date.

F3 · derivative.expiration_date: The RSUs vest over a four year period, with 25% of the RSUs vesting on each yearly anniversary of the date of grant, March 3, 2025, subject to the Reporting Person's continued service to Issuer through each vesting date.

SEC source: 0000950170-25-032891 · ownership.xml · derivative · entry 1

Mahoney Stephen F. · CIK 0001741389 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 440,565

Underlying: Common Stock · 440,565 shares

Expires 2035-03-03

F1 · derivative.exercise_date: The option vests and becomes exercisable in 48 equal monthly installments following the date of the grant, subject to the Reporting Person's continued service to Issuer through each vesting date. The date of the grant is March 3, 2025.

SEC source: 0000950170-24-110484 · ownership.xml · nonDerivative · entry 1

Mahoney Stephen F. · CIK 0001741389 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 21,400

SEC source: 0000950170-23-057519 · ownership.xml · derivative · entry 1

Mahoney Stephen F. · CIK 0001741389 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,259,400

Underlying: Common Stock · 1,259,400 shares

Expires 2033-10-30

F1 · derivative.exercise_date: The option vests as to 25% on October 30, 2024 and then in equal monthly installments over the following 36 months, subject to the Reporting Person's continued service to Issuer through each vesting date.

SEC source: 0000899243-22-037433 · doc4.xml · nonDerivative · entry 1

Mahoney Stephen F. · CIK 0001741389 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 17,264

F1 · kind: The reporting person is voluntarily reporting the acquisition of shares of the Issuer's common stock pursuant to the Magenta Therapeutics, Inc. 2019 Employee Stock Purchase Plan (the "ESPP") for the ESPP purchase period of June 1, 2022 through November 30, 2022. This transaction is exempt under both Rule 16b-3(c) and Rule 16b-3(d).

F2 · price: In accordance with the ESPP, these shares were purchased based on 85% of the closing price of the Issuer's common stock on June 1, 2022.

SEC source: 0000899243-22-027266 · doc4.xml · derivative · entry 1

Mahoney Stephen F. · CIK 0001741389 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 130,000

Underlying: Common Stock · 130,000 shares

Expires 2032-07-31

F1 · derivative.exercise_date: This option shall vest and become exercisable in 16 equal quarterly installments beginning on the first quarter following the vesting commencement date. The vesting commencement date is August 1, 2022.

SEC source: 0000899243-22-018804 · doc4.xml · derivative · entry 1

Mahoney Stephen F. · CIK 0001741389 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 62,500

Underlying: Common Stock · 62,500 shares

Expires 2032-05-16

F1 · derivative.exercise_date: This option shall vest and become exercisable in three equal installments, each installment vesting every six months, over the 18 months following the vesting commencement date. The vesting commencement date is May 15, 2022.

SEC source: 0000899243-22-006814 · doc4.xml · derivative · entry 1

Mahoney Stephen F. · CIK 0001741389 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 130,000

Underlying: Common Stock · 130,000 shares

Expires 2032-02-14

F1 · derivative.exercise_date: This option shall vest and become exercisable in 16 equal quarterly installments beginning on the first quarter following the vesting commencement date. The vesting commencement date is February 1, 2022.

SEC source: 0000899243-21-036601 · doc4.xml · nonDerivative · entry 1

Mahoney Stephen F. · CIK 0001741389 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 14,264

F1 · kind: This transaction represents shares sold solely to pay taxes due upon the vesting of restricted stock units, as disclosed by the reporting person on the Form 4 filed on September 16, 2021.

F2 · price: The price reported in column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $6.60 to $6.87, inclusive. 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.

SEC source: 0000899243-21-036337 · doc4.xml · nonDerivative · entry 1

Mahoney Stephen F. · CIK 0001741389 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 20,000

F1 · kind: On February 11, 2021, the reporting person was granted 40,000 restricted stock units. The restricted stock units vest in two equal installments subject to the achievement of certain performance milestones related to the issuer's business plans. The first performance milestone was achieved, resulting in vesting of 20,000 restricted stock units and the corresponding issuance of 20,000 shares of issuer common stock.

SEC source: 0000899243-20-030392 · doc4.xml · derivative · entry 1

Mahoney Stephen F. · CIK 0001741389 · See Remarks

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 435,000

Underlying: Common Stock · 435,000 shares

Expires 2030-11-01

F1 · derivative.exercise_date: This option shall vest and become exerciseable over four years, with 25% of this option vesting on November 2, 2021, and the remainder vesting in 36 equal monthly installments thereafter.

SEC source: 0001179110-19-010490 · edgar.xml · derivative · entry 1

Mahoney Stephen F. · CIK 0001741389 · President & COO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 82,000

Underlying: Class A Common Shares · 82,000 shares

Expires 2029-09-16

F1 · derivative.exercise_date: The option vests and becomes exercisable as to 25% of the total grant on the first anniversary of the vesting commencement date and vests in thirty-six equal monthly installments thereafter. The vesting commencement date is September 17, 2019.

SEC source: 0001104659-19-013176 · a4.xml · derivative · entry 1

Mahoney Stephen F. · CIK 0001741389 · President & COO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 83,000

Underlying: Class A Common Shares · 83,000 shares

Expires 2029-03-03

F1 · derivative.exercise_date: The option vests and becomes exercisable as to 25% of the total grant on the first anniversary of the vesting commencement date and vests in thirty-six equal monthly installments thereafter. The vesting commencement date is March 4, 2019.

SEC source: 0001104659-18-058109 · a4.xml · derivative · entry 1

Mahoney Stephen F. · CIK 0001741389 · President & COO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 50,000

Underlying: Class A Common Shares · 50,000 shares

Expires 2028-09-19

F1 · derivative.exercise_date: The option vests and becomes exercisable as to 25% of the total grant on the first anniversary of the vesting commencement date and vests in equal monthly installments over a three-year period thereafter. The vesting commencement date is September 20, 2018.

SEC source: 0001104659-18-036484 · a4.xml · derivative · entry 6

Mahoney Stephen F. · CIK 0001741389 · President & COO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 656,027

Underlying: Class A Common Shares · 107,050 shares

Expires not disclosed

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

F4 · derivative.exercise_price: Each share of Class B Common Shares is convertible at any time at the election of the holder, subject to certain contractual arrangements entered into between the Reporting Person and the Issuer, into one share of Class A Common Shares or one share of Class B1 Common Shares and will automatically convert into Class A Common Shares upon transfer to an unaffiliated party.

F4 · derivative.exercise_date: Each share of Class B Common Shares is convertible at any time at the election of the holder, subject to certain contractual arrangements entered into between the Reporting Person and the Issuer, into one share of Class A Common Shares or one share of Class B1 Common Shares and will automatically convert into Class A Common Shares upon transfer to an unaffiliated party.

F4 · derivative.expiration_date: Each share of Class B Common Shares is convertible at any time at the election of the holder, subject to certain contractual arrangements entered into between the Reporting Person and the Issuer, into one share of Class A Common Shares or one share of Class B1 Common Shares and will automatically convert into Class A Common Shares upon transfer to an unaffiliated party.

SEC source: 0001104659-18-036484 · a4.xml · derivative · entry 5

Mahoney Stephen F. · CIK 0001741389 · President & COO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Class A Common Shares · 6,392 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: Upon closing of the Issuer's initial public offering, the preferred shares automatically converted into the Issuer's Class A Common Shares on a one-for-one basis.

F1 · derivative.exercise_date: Upon closing of the Issuer's initial public offering, the preferred shares automatically converted into the Issuer's Class A Common Shares on a one-for-one basis.

F1 · derivative.expiration_date: Upon closing of the Issuer's initial public offering, the preferred shares automatically converted into the Issuer's Class A Common Shares on a one-for-one basis.

SEC source: 0001104659-18-036484 · a4.xml · derivative · entry 4

Mahoney Stephen F. · CIK 0001741389 · President & COO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

Underlying: Class B Common Shares · 107,050 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.

F3 · derivative.exercise_price: Upon closing of the Issuer's initial public offering, the preferred shares automatically converted into the Issuer's Class B Common Shares on a one-for-one basis.

F3 · derivative.exercise_date: Upon closing of the Issuer's initial public offering, the preferred shares automatically converted into the Issuer's Class B Common Shares on a one-for-one basis.

F3 · derivative.expiration_date: Upon closing of the Issuer's initial public offering, the preferred shares automatically converted into the Issuer's Class B Common Shares on a one-for-one basis.

SEC source: 0001104659-18-036484 · a4.xml · nonDerivative · entry 1

Mahoney Stephen F. · CIK 0001741389 · President & COO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 79,589

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.

SEC source: 0001104659-18-036484 · a4.xml · derivative · entry 3

Mahoney Stephen F. · CIK 0001741389 · President & COO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 6,392

Underlying: Class A Common Shares · 6,392 shares

Expires not disclosed

F1 · derivative.exercise_price: Upon closing of the Issuer's initial public offering, the preferred shares automatically converted into the Issuer's Class A Common Shares on a one-for-one basis.

F2 · shares: Reflects the 1-for-2.73235 share consolidation effected May 11, 2018.

F2 · price: Reflects the 1-for-2.73235 share consolidation effected May 11, 2018.

F1 · derivative.exercise_date: Upon closing of the Issuer's initial public offering, the preferred shares automatically converted into the Issuer's Class A Common Shares on a one-for-one basis.

F1 · derivative.expiration_date: Upon closing of the Issuer's initial public offering, the preferred shares automatically converted into the Issuer's Class A Common Shares on a one-for-one basis.

F2 · derivative.underlying_shares: Reflects the 1-for-2.73235 share consolidation effected May 11, 2018.

F2 · balance_after: Reflects the 1-for-2.73235 share consolidation effected May 11, 2018.