X0508 4 2024-12-10 0001701732 Altair Engineering Inc. ALTR 0001720642 Dias Nelson C/O ALTAIR ENGINEERING INC. 1820 E. BIG BEAVER RD. TROY MI 48083 1 Chief Revenue Officer 0 Class A Common Stock 2024-12-10 4 M 0 22500 0 A 70937 D Class A Common Stock 2024-12-10 4 S 0 22500 106.2258 D 48437 D Stock Option (Right to Buy) 39.82 2024-12-10 4 M 0 22500 0 D 2030-06-02 Class A Common Stock 22500 0 D Includes 21,443 Class A Common Stock restricted stock units that are unvested. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $106.085 to $106.81 per share, inclusive. The reporting person undertakes to provide to Altair Engineering Inc., any security holder of Altair Engineering Inc., 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 ranges set forth herein. The options vested in 2 equal installments commencing June 2, 2022. This option is currently fully vested. /s/ Raoul Maitra, attorney-in-fact for Nelson Navin Patrick Dias 2024-12-11