SSD · Simpson Manufacturing Co., Inc.

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.

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

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.

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

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.

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

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.

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

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

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

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

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.

Includes 2,814 Restricted Stock Units that have not yet vested.

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.

Includes 3,987 Restricted Stock Units that have not yet vested.

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.

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.

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.

Includes 2,624 Restricted Stock Units that have not yet vested.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Includes 1,913 restricted stock units that have not yet vested.

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.

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.

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.

Includes 3,091 restricted stock units that have not yet vested.

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.

Includes 4,389 Restricted Stock Units that have not yet vested.

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.

Includes 4,740 Restricted Stock Units that have not yet vested.

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.

Includes 773 restricted stock units that have not yet vested.

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.

Includes 2,994 restricted stock units that have not yet vested.

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.

Includes 3,741 Restricted Stock Units that have not yet vested.

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.

Includes 4,150 restricted stock units that have not yet vested.

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.

Includes 25,470 Restricted Stock Units that have not yet vested.

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.

Includes Restricted Stock Units that have not yet vested.

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.

Includes Restricted Stock Units that have not yet vested.

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.

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.

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

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.

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

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.

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

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.

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

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

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

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

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.

Includes Restricted Stock Units that have not yet vested.

Includes Restricted Stock Units that have not yet vested.

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.

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.

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.

Includes 2,635 restricted stock units that have not yet vested and 774 shares of common stock deferred under the Plan which will settle pursuant to the applicable terms of the Reporting Person's deferral election.

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.

Includes 3,419 Restricted Stock Units that have not yet vested.

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.

Includes 2,108 restricted stock units that have not yet vested.

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.

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.

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.

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.

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.

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.

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.

Includes 2,362 Restricted Stock Units that have not yet vested.

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.

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.