SSD

SEC source: 0001628280-26-061579 · wk-form4_1789159468.xml · nonDerivative · entry 1

Olosky Michael · CIK 0001833593 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 51,398

F1 · price: The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $172.83 to $172.91, inclusive. The reporting person undertakes to provide to the Company, any security holder of the Company or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

F2 · balance_after: Includes Restricted Stock Units that have not yet vested and shares of common stock deferred under the Simpson Manufacturing Co., Inc. Nonqualified Plan (the "Plan") which will settle pursuant to the applicable terms of the reporting person's deferral election. Also includes an additional 4 shares not previously reported due to an administrative error.

SEC source: 0001628280-26-058489 · wk-form4_1787352332.xml · nonDerivative · entry 1

Bullock Nozomi · CIK 0002098378 · EVP, Human Resources

10b5-1 filing: No plan indicated

Ownership: Indirect · By Trust (PSP)

Disclosed balance after: 0

F1 · kind: The transaction constitutes an intra-plan transfer from the company stock fund to another investment option under the Simpson Manufacturing Co., Inc. Profit Sharing Plan for Salaried Employees (the "Plan"). The transaction was a discretionary transaction exempt under Rule 16b-3(f). These shares were not previously reported due to an administrative error.

F2 · ownership.nature: The shares are owned by the Simpson Manufacturing Co., Inc. Profit Sharing Plan for Salaried Employees (the "Plan") of which the reporting person is a participant. The Plan is qualified under sections 401(a)(26) and 410 of the Internal Revenue Code.

SEC source: 0001628280-26-053491 · wk-form4_1785963804.xml · nonDerivative · entry 1

ANDRASICK JAMES S · CIK 0001206906 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 61

SEC source: 0001628280-26-032950 · wk-form4_1778272269.xml · nonDerivative · entry 1

Knight Kenneth D. · CIK 0001817388 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 4,775

F1 · shares: At the election of the Reporting Person, the restricted stock units acquired pursuant to this filing have been deferred under the Simpson Manufacturing Co., Inc. Nonqualified Plan (the "Plan") and will be settled in shares of common stock on a future date selected by the Reporting Person at the time of his or her deferral election.

F2 · shares: Represents 678 restricted stock units acquired pursuant to the Company's non-employee director compensation policy.

F3 · balance_after: Includes 2,828 restricted stock units deferred under the Plan which will settle in shares of common stock pursuant to the applicable terms of the Reporting Person's deferral election.

SEC source: 0001628280-26-032948 · wk-form4_1778272263.xml · nonDerivative · entry 1

FORD CELESTE VOLZ · CIK 0001397729 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 14,112

F1 · shares: Represents 678 shares acquired pursuant to the Company's non-employee director compensation policy.

SEC source: 0001628280-26-032945 · wk-form4_1778272255.xml · nonDerivative · entry 1

Drake Angela C · CIK 0001807854 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,691

F1 · shares: Represents 678 restricted stock units acquired pursuant to the Company's non-employee director compensation policy.

SEC source: 0001628280-26-032943 · wk-form4_1778272247.xml · nonDerivative · entry 1

Donaldson Philip E · CIK 0001737667 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 7,015

F1 · shares: Represents 929 shares acquired pursuant to the Company's non-employee director compensation policy.

SEC source: 0001628280-26-032942 · wk-form4_1778272241.xml · nonDerivative · entry 1

Coney Felica · CIK 0001979605 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 3,019

F1 · shares: Represents 678 restricted stock units acquired pursuant to the Company's non-employee director compensation policy.

SEC source: 0001628280-26-032940 · wk-form4_1778272228.xml · nonDerivative · entry 1

Banks Chau · CIK 0001816462 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 3,019

F1 · shares: At the election of the Reporting Person, the restricted stock units acquired pursuant to this filing have been deferred under the Simpson Manufacturing Co., Inc. Nonqualified Plan (the "Plan") and will be settled in shares of common stock on a future date selected by the Reporting Person at the time of his or her deferral election.

F2 · shares: Represents 678 shares acquired pursuant to the Company's non-employee director compensation policy.

F3 · balance_after: Includes 2,103 restricted stock units deferred under the Plan which will settle in shares of common stock pursuant to the applicable terms of the Reporting Person's deferral election.

SEC source: 0001628280-26-032936 · wk-form4_1778272203.xml · nonDerivative · entry 1

ANDRASICK JAMES S · CIK 0001206906 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 861

F1 · shares: Represents 678 shares acquired pursuant to the Company's non-employee director compensation policy.

SEC source: 0001628280-26-009264 · wk-form4_1771453707.xml · nonDerivative · entry 2

Payton Cassandra · CIK 0002003832 · EVP, General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 4,688

F2 · shares: Represents shares of common stock withheld by the Company to satisfy the tax withholding obligation for the reporting person's performance stock units that settled on February 17, 2026, and restricted stock units that vested on February 17, 2026.

F3 · balance_after: Includes 2,624 Restricted Stock Units that have not yet vested.

SEC source: 0001628280-26-009264 · wk-form4_1771453707.xml · nonDerivative · entry 1

Payton Cassandra · CIK 0002003832 · EVP, General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,437

F1 · shares: Represents performance stock units granted in January 2023, for which the performance and vesting periods ended December 31, 2025, and for which the settlement date was February 17, 2026.

SEC source: 0001628280-26-009263 · wk-form4_1771453701.xml · nonDerivative · entry 1

Mehta Udit · CIK 0002022638 · Chief Technology Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 4,990

F1 · shares: Represents shares of common stock withheld by the Company to satisfy the tax withholding obligation for the reporting person's restricted stock units that vested on February 17, 2026.

F2 · balance_after: Includes 2,814 Restricted Stock Units that have not yet vested.

SEC source: 0001628280-26-009262 · wk-form4_1771453695.xml · nonDerivative · entry 2

Gilstrap Jeremy · CIK 0001959672 · EVP, Innovation

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 10,900

F3 · shares: Represents shares of common stock withheld by the Company to satisfy the tax withholding obligation for the reporting person's performance stock units that settled on February 17, 2026, and restricted stock units that vested on February 17, 2026.

F4 · balance_after: Includes 1,958 restricted stock units that have not yet vested and 2,774 shares of common stock deferred under the Plan which will settle pursuant to the applicable terms of the Reporting Person's deferral election.

SEC source: 0001628280-26-009262 · wk-form4_1771453695.xml · nonDerivative · entry 1

Gilstrap Jeremy · CIK 0001959672 · EVP, Innovation

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 11,318

F1 · shares: At the election of the Reporting Person, a portion of the shares of common stock acquired pursuant to this filing have been deferred under the Simpson Manufacturing Co., Inc. Nonqualified Plan (the "Plan") and will settle on a future date selected by the Reporting Person at the time of his or her deferral election.

F2 · shares: Represents performance stock units granted in January 2023, for which the performance and vesting periods ended December 31, 2025, and for which the settlement date was February 17, 2026.

SEC source: 0001628280-26-009261 · wk-form4_1771453687.xml · nonDerivative · entry 1

Dunn Matt · CIK 0002025742 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 4,687

F1 · shares: Represents shares of common stock withheld by the Company to satisfy the tax withholding obligation for the reporting person's restricted stock units that vested on February 17, 2026.

F2 · balance_after: Includes 3,987 Restricted Stock Units that have not yet vested.

SEC source: 0001628280-26-009260 · wk-form4_1771453683.xml · nonDerivative · entry 2

Burton Phillip · CIK 0001959680 · EVP, North America

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,907

F3 · shares: Represents shares of common stock withheld by the Company to satisfy the tax withholding obligation for the reporting person's restricted stock units that vested on February 17, 2026.

F4 · balance_after: Includes 2,743 restricted stock units that have not yet vested and 4,022 shares of common stock deferred under the Plan which will settle pursuant to the applicable terms of the Reporting Person's deferral election.

SEC source: 0001628280-26-009260 · wk-form4_1771453683.xml · nonDerivative · entry 1

Burton Phillip · CIK 0001959680 · EVP, North America

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 10,251

F1 · shares: At the election of the Reporting Person, the shares of common stock acquired pursuant to this filing have been deferred under the Simpson Manufacturing Co., Inc. Nonqualified Plan (the "Plan") and will settle on a future date selected by the Reporting Person at the time of his or her deferral election.

F2 · shares: Represents performance stock units granted in January 2023, for which the performance and vesting periods ended December 31, 2025, and for which the settlement date was February 17, 2026.

SEC source: 0001628280-26-009259 · wk-form4_1771453677.xml · nonDerivative · entry 1

Andersen Michael · CIK 0001959617 · EVP, Europe

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 12,417

F1 · shares: Represents performance stock units granted in January 2023, for which the performance and vesting periods ended December 31, 2025, and for which the settlement date was February 17, 2026.

F2 · balance_after: Includes 1,913 restricted stock units that have not yet vested.

SEC source: 0001628280-26-009257 · wk-form4_1771453669.xml · nonDerivative · entry 2

Olosky Michael · CIK 0001833593 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 54,896

F3 · shares: Represents shares of common stock withheld by the Company to satisfy the tax withholding obligation for the reporting person's restricted stock units that vested on February 17, 2026.

F4 · balance_after: Includes 17,210 restricted stock units that have not yet vested and 34,188 shares of common stock deferred under the Plan which will settle pursuant to the applicable terms of the Reporting Person's deferral election.

SEC source: 0001628280-26-009257 · wk-form4_1771453669.xml · nonDerivative · entry 1

Olosky Michael · CIK 0001833593 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 56,478

F1 · shares: At the election of the Reporting Person, the shares of common stock acquired pursuant to this filing have been deferred under the Simpson Manufacturing Co., Inc. Nonqualified Plan (the "Plan") and will settle on a future date selected by the Reporting Person at the time of his or her deferral election.

F2 · shares: Represents performance stock units granted in January 2023, for which the performance and vesting periods ended December 31, 2025, and for which the settlement date was February 17, 2026.

SEC source: 0001628280-26-004187 · wk-form4_1769723816.xml · nonDerivative · entry 1

Payton Cassandra · CIK 0002003832 · EVP, General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 4,474

F1 · shares: Represents Restricted Stock Units (RSUs). Each RSU represents a right to receive, subject to the terms and conditions of the 2011 Equity Incentive Plan and an RSU Award Agreement, one share of the Company's common stock subject to vesting in three equal annual installments, beginning in February 2027.

F2 · balance_after: Includes 3,741 Restricted Stock Units that have not yet vested.

SEC source: 0001628280-26-004186 · wk-form4_1769723809.xml · nonDerivative · entry 1

Mehta Udit · CIK 0002022638 · Chief Technology Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 5,376

F1 · shares: Represents Restricted Stock Units (RSUs). Each RSU represents a right to receive, subject to the terms and conditions of the 2011 Equity Incentive Plan and an RSU Award Agreement, one share of the Company's common stock subject to vesting in three equal annual installments, beginning in February 2027.

F2 · balance_after: Includes 4,389 Restricted Stock Units that have not yet vested.

SEC source: 0001628280-26-004185 · wk-form4_1769723803.xml · nonDerivative · entry 1

Gilstrap Jeremy · CIK 0001959672 · EVP, Innovation

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,869

F1 · shares: Represents Restricted Stock Units (RSUs). Each RSU represents a right to receive, subject to the terms and conditions of the 2011 Equity Incentive Plan and an RSU Award Agreement, one share of the Company's common stock subject to vesting in three equal annual installments, beginning in February 2027.

F2 · balance_after: Includes 2,994 restricted stock units that have not yet vested.

SEC source: 0001628280-26-004183 · wk-form4_1769723797.xml · nonDerivative · entry 1

Dunn Matt · CIK 0002025742 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 4,872

F1 · shares: Represents Restricted Stock Units (RSUs). Each RSU represents a right to receive, subject to the terms and conditions of the 2011 Equity Incentive Plan and an RSU Award Agreement, one share of the Company's common stock subject to vesting in three equal annual installments, beginning in February 2027.

F2 · balance_after: Includes 4,740 Restricted Stock Units that have not yet vested.

SEC source: 0001628280-26-004182 · wk-form4_1769723788.xml · nonDerivative · entry 1

Burton Phillip · CIK 0001959680 · EVP, North America

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 7,003

F1 · shares: Represents Restricted Stock Units (RSUs). Each RSU represents a right to receive, subject to the terms and conditions of the 2011 Equity Incentive Plan and an RSU Award Agreement, one share of the Company's common stock subject to vesting in three equal annual installments, beginning in February 2027.

F2 · balance_after: Includes 4,150 restricted stock units that have not yet vested.

SEC source: 0001628280-26-004180 · wk-form4_1769723783.xml · nonDerivative · entry 1

Bullock Nozomi · CIK 0002098378 · EVP, Human Resources

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 773

F1 · shares: Represents Restricted Stock Units (RSUs). Each RSU represents a right to receive, subject to the terms and conditions of the 2011 Equity Incentive Plan and an RSU Award Agreement, one share of the Company's common stock subject to vesting in three equal annual installments, beginning in February 2027.

F2 · balance_after: Includes 773 restricted stock units that have not yet vested.

SEC source: 0001628280-26-004179 · wk-form4_1769723777.xml · nonDerivative · entry 1

Andersen Michael · CIK 0001959617 · EVP, Europe

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,793

F1 · shares: Represents Restricted Stock Units (RSUs). Each RSU represents a right to receive, subject to the terms and conditions of the 2011 Equity Incentive Plan and an RSU Award Agreement, one share of the Company's common stock subject to vesting in three equal annual installments, beginning in February 2027.

F2 · balance_after: Includes 3,091 restricted stock units that have not yet vested.

SEC source: 0001628280-26-004178 · wk-form4_1769723771.xml · nonDerivative · entry 1

Olosky Michael · CIK 0001833593 · Director · President and CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 39,338

F1 · shares: Represents Restricted Stock Units (RSUs). Each RSU represents a right to receive, subject to the terms and conditions of the 2011 Equity Incentive Plan and an RSU Award Agreement, one share of the Company's common stock subject to vesting in three equal annual installments, beginning in February 2027.

F2 · balance_after: Includes 25,470 Restricted Stock Units that have not yet vested.

SEC source: 0001628280-25-057172 · wk-form4_1765840425.xml · nonDerivative · entry 1

Donaldson Philip E · CIK 0001737667 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 6,086

SEC source: 0001628280-25-051695 · wk-form4_1762985480.xml · nonDerivative · entry 1

ANDRASICK JAMES S · CIK 0001206906 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 183

SEC source: 0000920371-25-000118 · wk-form4_1756256433.xml · nonDerivative · entry 1

Andersen Michael · CIK 0001959617 · EVP, Europe

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 7,810

F1 · price: The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $196.12 to $196.14, inclusive. The reporting person undertakes to provide to the Company, any security holder of the Company or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

F2 · balance_after: Includes Restricted Stock Units that have not yet vested.

SEC source: 0000920371-25-000109 · wk-form4_1754339499.xml · nonDerivative · entry 1

Gilstrap Jeremy · CIK 0001959672 · EVP, Innovation

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 7,794

F1 · price: The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $178.23 to $178.53, inclusive. The reporting person undertakes to provide to the Company, any security holder of the Company or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

F2 · balance_after: Includes Restricted Stock Units that have not yet vested.

SEC source: 0000920371-25-000099 · wk-form4_1747345140.xml · nonDerivative · entry 1

ANDRASICK JAMES S · CIK 0001206906 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 783

F1 · price: The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $165.13 to $165.62, inclusive. The reporting person undertakes to provide to the Company, any security holder of the Company or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

SEC source: 0000920371-25-000089 · wk-form4_1746737134.xml · nonDerivative · entry 1

Knight Kenneth D. · CIK 0001817388 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 4,097

F1 · shares: At the election of the Reporting Person, the restricted stock units acquired pursuant to this filing have been deferred under the Simpson Manufacturing Co., Inc. Nonqualified Plan (the "Plan") and will be settled in shares of common stock on a future date selected by the Reporting Person at the time of his or her deferral election.

F2 · shares: Represents 783 restricted stock units acquired pursuant to the Company's non-employee director compensation policy.

F3 · balance_after: Includes 2,150 restricted stock units deferred under the Plan which will settle in shares of common stock pursuant to the applicable terms of the Reporting Person's deferral election.

SEC source: 0000920371-25-000088 · wk-form4_1746737124.xml · nonDerivative · entry 1

FORD CELESTE VOLZ · CIK 0001397729 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 13,434

F1 · shares: Represents 783 shares acquired pursuant to the Company's non-employee director compensation policy.

SEC source: 0000920371-25-000087 · wk-form4_1746737112.xml · nonDerivative · entry 1

Drake Angela C · CIK 0001807854 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,013

F1 · shares: Represents 783 restricted stock units acquired pursuant to the Company's non-employee director compensation policy.

SEC source: 0000920371-25-000086 · wk-form4_1746737102.xml · nonDerivative · entry 1

Donaldson Philip E · CIK 0001737667 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,461

F1 · shares: Represents 1,072 shares acquired pursuant to the Company's non-employee director compensation policy.

SEC source: 0000920371-25-000084 · wk-form4_1746737080.xml · nonDerivative · entry 1

Banks Chau · CIK 0001816462 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 2,341

F1 · shares: At the election of the Reporting Person, the restricted stock units acquired pursuant to this filing have been deferred under the Simpson Manufacturing Co., Inc. Nonqualified Plan (the "Plan") and will be settled in shares of common stock on a future date selected by the Reporting Person at the time of his or her deferral election.

F2 · shares: Represents 783 shares acquired pursuant to the Company's non-employee director compensation policy.

F3 · balance_after: Includes 1,425 restricted stock units deferred under the Plan which will settle in shares of common stock pursuant to the applicable terms of the Reporting Person's deferral election.

SEC source: 0000920371-25-000085 · wk-form4_1746737091.xml · nonDerivative · entry 1

Coney Felica · CIK 0001979605 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 2,341

F1 · shares: Represents 783 restricted stock units acquired pursuant to the Company's non-employee director compensation policy.

SEC source: 0000920371-25-000083 · wk-form4_1746737069.xml · nonDerivative · entry 1

ANDRASICK JAMES S · CIK 0001206906 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,649

F1 · shares: Represents 783 shares acquired pursuant to the Company's non-employee director compensation policy.

SEC source: 0000920371-25-000070 · wk-form4_1746477059.xml · nonDerivative · entry 1

Lutz Jennifer · CIK 0001959616 · EVP, Human Resources

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 4,047

F1 · price: The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $154.44 to $154.46, inclusive. The reporting person undertakes to provide to the Company, any security holder of the Company or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.

F2 · balance_after: Includes Restricted Stock Units that have not yet vested.

SEC source: 0000920371-25-000046 · wk-form4_1740692401.xml · nonDerivative · entry 1

Andersen Michael · CIK 0001959617 · EVP, Europe

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 8,810

F1 · balance_after: Includes Restricted Stock Units that have not yet vested.

SEC source: 0000920371-25-000044 · wk-form4_1740015739.xml · nonDerivative · entry 1

Payton Cassandra · CIK 0002003832 · EVP, General Counsel

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 3,095

F1 · shares: Represents shares of common stock withheld by the Company to satisfy the tax withholding obligation for the reporting person's restricted stock units that vested on February 18, 2025.

F2 · balance_after: Includes 2,362 Restricted Stock Units that have not yet vested.

SEC source: 0000920371-25-000043 · wk-form4_1740015729.xml · nonDerivative · entry 1

Mehta Udit · CIK 0002022638 · Chief Technology Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 4,406

F1 · shares: Represents shares of common stock withheld by the Company to satisfy the tax withholding obligation for the reporting person's restricted stock units that vested on February 18, 2025.

F2 · balance_after: Includes 3,419 Restricted Stock Units that have not yet vested.

SEC source: 0000920371-25-000042 · wk-form4_1740015719.xml · nonDerivative · entry 2

Lutz Jennifer · CIK 0001959616 · EVP, Human Resources

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 4,377

F3 · shares: Represents shares of common stock withheld by the Company to satisfy the tax withholding obligation for the reporting person's restricted stock units that vested on February 18, 2025.

F4 · balance_after: Includes 1,419 restricted stock units that have not yet vested and 1,738 shares of common stock deferred under the Plan which will settle pursuant to the applicable terms of the Reporting Person's deferral election.

SEC source: 0000920371-25-000042 · wk-form4_1740015719.xml · nonDerivative · entry 1

Lutz Jennifer · CIK 0001959616 · EVP, Human Resources

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 4,416

F1 · shares: At the election of the Reporting Person, the shares of common stock acquired pursuant to this filing have been deferred under the Simpson Manufacturing Co., Inc. Nonqualified Plan (the "Plan") and will settle on a future date selected by the Reporting Person at the time of his or her deferral election.

F2 · shares: Represents performance stock units granted in January 2022, for which the performance and vesting periods ended December 31, 2024, and for which the settlement date was February 18, 2025.

SEC source: 0000920371-25-000041 · wk-form4_1740015709.xml · nonDerivative · entry 2

Gilstrap Jeremy · CIK 0001959672 · EVP, Innovation

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 10,294

F3 · shares: Represents shares of common stock withheld by the Company to satisfy the tax withholding obligation for the reporting person's performance stock units that settled on February 18, 2025, and restricted stock units that vested on February 18, 2025.

F4 · balance_after: Includes 1,919 restricted stock units that have not yet vested and 999 shares of common stock deferred under the Plan which will settle pursuant to the applicable terms of the Reporting Person's deferral election.

SEC source: 0000920371-25-000041 · wk-form4_1740015709.xml · nonDerivative · entry 1

Gilstrap Jeremy · CIK 0001959672 · EVP, Innovation

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 10,485

F1 · shares: At the election of the Reporting Person, a portion of the shares of common stock acquired pursuant to this filing have been deferred under the Simpson Manufacturing Co., Inc. Nonqualified Plan (the "Plan") and will settle on a future date selected by the Reporting Person at the time of his or her deferral election.

F2 · shares: Represents performance stock units granted in January 2022, for which the performance and vesting periods ended December 31, 2024, and for which the settlement date was February 18, 2025.

SEC source: 0000920371-25-000040 · wk-form4_1740015698.xml · nonDerivative · entry 1

Dunn Matt · CIK 0002025742 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 2,205

F1 · shares: Represents shares of common stock withheld by the Company to satisfy the tax withholding obligation for the reporting person's restricted stock units that vested on February 18, 2025.

F2 · balance_after: Includes 2,073 Restricted Stock Units that have not yet vested.