MGNI

The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 20, 2025.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $20.31 to $21.25, inclusive. The Reporting Person undertakes 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 sold at each separate price within the range set forth in this footnote to this Form 4.

The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 11, 2025.

The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 10, 2025.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $21.00 to $21.16, inclusive. The Reporting Person undertakes 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 sold at each separate price within the range set forth in this footnote to this Form 4.

The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 11, 2025.

This exercise and subsequent sale were made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 13, 2026.

This exercise and subsequent sale were made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 13, 2026.

This exercise and subsequent sale were made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 13, 2026.

Granted as compensation for services.

The stock options have fully vested and are immediately exercisable.

The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 11, 2025.

The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 10, 2025.

This exercise and subsequent sale were made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 13, 2026.

Granted as compensation for services.

The stock options have fully vested and are immediately exercisable.

This exercise and subsequent sale were made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 13, 2026.

This exercise and subsequent sale were made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 13, 2026.

The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 12, 2025.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $18.00 to 18.25, inclusive. The Reporting Person undertakes 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 sold at each separate price within the range set forth in this footnote to this Form 4.

The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 11, 2025.

This exercise and subsequent sale were made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 13, 2026.

Granted as compensation for services.

The stock options have fully vested and are immediately exercisable.

This exercise and subsequent sale were made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 13, 2026.

This exercise and subsequent sale were made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 13, 2026.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.945 to $16.93, inclusive. The Reporting Person undertakes 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 sold at each separate price within the range set forth in this footnote to this Form 4.

The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 11, 2025.

The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 9, 2026.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.285 to $15.88, inclusive. The Reporting Person undertakes 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 sold at each separate price within the range set forth in this footnote to this Form 4.

The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 12, 2025.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.29 to $15.90, inclusive. The Reporting Person undertakes 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 sold at each separate price within the range set forth in this footnote to this Form 4.

Represents restricted stock units that vest in full on the earliest of (i) June 8, 2027, (ii) the date of the 2027 annual meeting of the Issuer's stockholders, or (iii) a change of control of the Issuer.

Granted as compensation for services.

Represents restricted stock units that vest in full on the earliest of (i) June 8, 2027, (ii) the date of the 2027 annual meeting of the Issuer's stockholders, or (iii) a change of control of the Issuer.

Granted as compensation for services.

Represents restricted stock units that vest in full on the earliest of (i) June 8, 2027, (ii) the date of the 2027 annual meeting of the Issuer's stockholders, or (iii) a change of control of the Issuer.

Granted as compensation for services.

Represents restricted stock units that vest in full on the earliest of (i) June 8, 2027, (ii) the date of the 2027 annual meeting of the Issuer's stockholders, or (iii) a change of control of the Issuer.

Granted as compensation for services.

Represents restricted stock units that vest in full on the earliest of (i) June 8, 2027, (ii) the date of the 2027 annual meeting of the Issuer's stockholders, or (iii) a change of control of the Issuer.

Granted as compensation for services.

Represents restricted stock units that vest in full on the earliest of (i) June 8, 2027, (ii) the date of the 2027 annual meeting of the Issuer's stockholders, or (iii) a change of control of the Issuer.

Granted as compensation for services.

Represents restricted stock units that vest in full on the earliest of (i) June 8, 2027, (ii) the date of the 2027 annual meeting of the Issuer's stockholders, or (iii) a change of control of the Issuer.

Granted as compensation for services.

Represents restricted stock units that vest in full on the earliest of (i) June 8, 2027, (ii) the date of the 2027 annual meeting of the Issuer's stockholders, or (iii) a change of control of the Issuer.

Granted as compensation for services.

The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 11, 2025.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $13.32 to $13.355, inclusive. The Reporting Person undertakes 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 sold at each separate price within the range set forth in this footnote.

Represents the non-discretionary forfeiture of shares on behalf of the Reporting Person pursuant to an arrangement mandated by the Issuer to cover the tax withholding obligations associated with the vesting of restricted stock units.

Includes 1,316 shares acquired by the Reporting Person on May 15, 2026 under the Issuer's Employee Stock Purchase Plan.

Represents the non-discretionary forfeiture of shares on behalf of the Reporting Person pursuant to an arrangement mandated by the Issuer to cover the tax withholding obligations associated with the vesting of restricted stock units.

Represents the non-discretionary forfeiture of shares on behalf of the Reporting Person pursuant to an arrangement mandated by the Issuer to cover the tax withholding obligations associated with the vesting of restricted stock units.

Represents the non-discretionary forfeiture of shares on behalf of the Reporting Person pursuant to an arrangement mandated by the Issuer to cover the tax withholding obligations associated with the vesting of restricted stock units.

Represents the non-discretionary forfeiture of shares on behalf of the Reporting Person pursuant to an arrangement mandated by the Issuer to cover the tax withholding obligations associated with the vesting of restricted stock units.

Includes 1,767 shares acquired by the Reporting Person on May 15, 2026 under the Issuer's Employee Stock Purchase Plan.

Represents the non-discretionary forfeiture of shares on behalf of the Reporting Person pursuant to an arrangement mandated by the Issuer to cover the tax withholding obligations associated with the vesting of restricted stock units.

Includes 433 shares acquired by the Reporting Person on May 15, 2026 under the Issuer's Employee Stock Purchase Plan.

Represents the non-discretionary forfeiture of shares on behalf of the Reporting Person pursuant to an arrangement mandated by the Issuer to cover the tax withholding obligations associated with the vesting of restricted stock units.

These sales were made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 18, 2025.

Represents the non-discretionary forfeiture of shares on behalf of the Reporting Person pursuant to an arrangement mandated by the Issuer to cover the tax withholding obligations associated with the vesting of restricted stock units.

Represents the non-discretionary forfeiture of shares on behalf of the Reporting Person pursuant to an arrangement mandated by the Issuer to cover the tax withholding obligations associated with the vesting of restricted stock units.

Represents the non-discretionary forfeiture of shares on behalf of the Reporting Person pursuant to an arrangement mandated by the Issuer to cover the tax withholding obligations associated with the vesting of restricted stock units.

Represents the non-discretionary forfeiture of shares on behalf of the Reporting Person pursuant to an arrangement mandated by the Issuer to cover the tax withholding obligations associated with the vesting of restricted stock units.

Represents the non-discretionary forfeiture of shares on behalf of the Reporting Person pursuant to an arrangement mandated by the Issuer to cover the tax withholding obligations associated with the vesting of restricted stock units.

Represents the non-discretionary forfeiture of shares on behalf of the Reporting Person pursuant to an arrangement mandated by the Issuer to cover the tax withholding obligations associated with the vesting of restricted stock units.

Represents the non-discretionary forfeiture of shares on behalf of the Reporting Person pursuant to an arrangement mandated by the Issuer to cover the tax withholding obligations associated with the vesting of restricted stock units.

Represents the non-discretionary forfeiture of shares on behalf of the Reporting Person pursuant to an arrangement mandated by the Issuer to cover the tax withholding obligations associated with the vesting of restricted stock units.

Each PSU represents a contingent right to receive, on vesting, one share of the Issuer's common stock, subject to Issuer performance as more specifically described in Footnote 4 herein.

Equity grant under the Company's Amended and Restated 2014 Equity Incentive Plan.

Vesting of the PSU was determined based on the Issuer's total stockholder return ("TSR") for the three-year period beginning on January 1, 2023 relative to the TSRs of the companies in the Russell 2000 index over that period. The number of PSUs reported in column 5 on the Form 4 filed with the Securities and Exchange Commission on January 4, 2023 reflected the target number of PSUs initially subject to the award. The award was eligible to vest as to 0% to 150% of the target number of PSUs. On January 9, 2026, the Compensation Committee of the Issuer's Board of Directors determined that, based on 126.35% achievement, the Reporting Person actually vested 64,125 shares.

Each PSU represents a contingent right to receive, on vesting, one share of the Issuer's common stock, subject to Issuer performance as more specifically described in Footnote 4 herein.

Equity grant under the Company's Amended and Restated 2014 Equity Incentive Plan.

Vesting of the PSU was determined based on the Issuer's total stockholder return ("TSR") for the three-year period beginning on January 1, 2023 relative to the TSRs of the companies in the Russell 2000 index over that period. The number of PSUs reported in column 5 on the Form 4 filed with the Securities and Exchange Commission on January 4, 2023 reflected the target number of PSUs initially subject to the award. The award was eligible to vest as to 0% to 150% of the target number of PSUs. On January 9, 2026, the Compensation Committee of the Issuer's Board of Directors determined that, based on 126.35% achievement, the Reporting Person actually vested 72,675 shares.

Equity grant under the Company's Amended and Restated 2014 Equity Incentive Plan.

Each PSU represents a contingent right to receive, on vesting, one share of the Issuer's common stock, subject to Issuer performance as more specifically described in Footnote 4 herein.

Equity grant under the Company's Amended and Restated 2014 Equity Incentive Plan.

Vesting of the PSU was determined based on the Issuer's total stockholder return ("TSR") for the three-year period beginning on January 1, 2023 relative to the TSRs of the companies in the Russell 2000 index over that period. The number of PSUs reported in column 5 on the Form 4 filed with the Securities and Exchange Commission on January 4, 2023 reflected the target number of PSUs initially subject to the award. The award was eligible to vest as to 0% to 150% of the target number of PSUs. On January 9, 2026, the Compensation Committee of the Issuer's Board of Directors determined that, based on 126.35% achievement, the Reporting Person actually vested 28,215 shares.