X0306 4 2020-11-13 0 0001701732 Altair Engineering Inc. ALTR 0001635563 Hart Richard C/O ALTAIR ENGINEERING INC. 1820 E. BIG BEAVER ROAD TROY MI 48083 1 0 0 0 Class A Common Stock 2020-11-13 4 M 0 8000 5.18 A 17000 D Class A Common Stock 2020-11-13 4 S 0 8000 48.975 D 9000 D Stock Option (right to buy) 5.18 2020-11-13 4 M 0 8000 0.00 D 2027-06-09 Class A Common Stock 8000 16000 D Consists of 4,500 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 $48.95 to $49.10 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 option became exercisable as to 50% of the shares on June 9, 2018 and the remaining shares vested on June 9, 2019. The option is currently fully vested. /s/ Raoul Maitra, attorney-in-fact for Richard J. Hart 2020-11-16