X0206 3 2017-10-31 0 0001701732 Altair Engineering Inc. ALTR 0001720809 Christ Revocable Trust C/O ALTAIR ENGINEERING INC. 1820 E. BIG BEAVER ROAD TROY MI 48083 0 0 1 0 Class B Common Stock 0.00 Class A Common Stock 9346728 D Each share of Class B common stock is immediately convertible, at the option of the shareholder, into one share of Class A common stock and shall automatically convert into Class A common stock upon the occurrence of certain events. Please see Altair Engineering Inc. Registration Statement filed with the Securities and Exchange Commission on Form S-1 (File No. 333-220710) for a description of the conversion rights. Exhibit List Exhibit 24 - Power of Attorney /s/ George J. Christ, Trustee, Christ Revocable Trust dated May 8, 2015 2017-10-31