X0306 4 2019-06-17 0 0001701732 Altair Engineering Inc. ALTR 0001720315 Morof Howard N C/O ALTAIR ENGINEERING INC. 1820 E. BIG BEAVER ROAD TROY MI 48083 0 1 0 0 Chief Financial Officer Class A Common Stock 2019-06-17 4 S 0 4000 37.524 D 359164 I By Howard N. Morof Revocable Trust dated August 7, 1992 Class A Common Stock 5368 D Class A Common Stock 141080 I By Howard N. Morof Irrevocable Grantor Trust dated September 11, 2017 The sale of the shares of Class A Common Stock were made pursuant to a plan intended to comply with Rule 10b5-1 of the Exchange Act, previously entered into on March 11, 2019. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $37.00 to $37.77 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 reporting person serves as trustee. Reporting person disclaims beneficial ownership of these securities except to the extent of his pecuniary interest therein, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of all of the reported shares for purposes of Section 16 or for any other purpose. Includes 4,851 Class A Common Stock restricted stock units that are unvested. /s/ Raoul Maitra, attorney-in-fact for Howard N. Morof 2019-06-19