SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* Gayle Brian (Last) (First) (Middle) C/O ALTAIR ENGINEERING INC. 1820 E. BIG BEAVER ROAD (Street) TROY MI 48083 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 03/17/2021	3. Issuer Name and Ticker or Trading Symbol Altair Engineering Inc. [ ALTR ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director 10% Owner X Officer (give title below) Other (specify below) Chief Accounting Officer	5. If Amendment, Date of Original Filed (Month/Day/Year)
			6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Class A Common Stock	15,649(1)	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (right to buy)	(2)	06/09/2027	Class A Common Stock	1,417	$5.18	D
Stock Option (right to buy)	(3)	03/16/2030	Class A Common Stock	1,091	$29.22	D
Stock Option (right to buy)	(4)	06/02/2030	Class A Common Stock	22,500	$39.82	D
Stock Option (right to buy)	(5)	12/02/2030	Class A Common Stock	22,500	$52.03	D
Stock Option (right to buy)	(6)	03/15/2031	Class A Common Stock	5,443	$61.93	D

Explanation of Responses:

1. Includes 3,853 Class A Common Stock restricted stock units that are unvested.

2. The options vest in 4 equal annual installments commencing on June 9, 2017.

3. The options vest in 4 equal annual installments commencing on March 16, 2021.

4. On June 2, 2020, the Reporting Person was granted options covering 22,500 shares of Class A Common Stock. Of such options, options covering 11,250 shares vest on June 2, 2022 and options covering 11,250 shares vest on June 2, 2023.

5. On December 2, 2020, the Reporting Person was granted options covering 22,500 shares of Class A Common Stock. Of such options, options covering 11,250 shares vest on December 2, 2022 and options covering 11,250 shares vest on December 2, 2023.

6. The options vest in 4 equal annual installments commencing on March 15, 2022.

Remarks:

Exhibit List Exhibit 24 - Power of Attorney

	/s/ Raoul Maitra, attorney-in-fact for Brian Gayle	03/18/2021
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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