SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* Scapa James Ralph (Last) (First) (Middle) C/O ALTAIR ENGINEERING INC. 1820 E. BIG BEAVER RD. (Street) TROY MI 48083 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol Altair Engineering Inc. [ ALTR ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director X 10% Owner X Officer (give title below) Other (specify below) Chief Executive Officer
	3. Date of Earliest Transaction (Month/Day/Year) 10/28/2024
	4. 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 Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Class A Common Stock	10/28/2024		C		6,500	A	$0	6,500	I	By James R. Scapa Declaration of Trust dated March 5, 1987(1)
Class A Common Stock	10/28/2024		S(2)		3,683(2)	D	$102.0806(3)	2,817	I	By James R. Scapa Declaration of Trust dated March 5, 1987(1)
Class A Common Stock	10/28/2024		S(2)		2,522(2)	D	$103.1924(4)	295	I	By James R. Scapa Declaration of Trust dated March 5, 1987(1)
Class A Common Stock	10/28/2024		S(2)		295(2)	D	$103.8409(5)	0	I	By James R. Scapa Declaration of Trust dated March 5, 1987(1)
Class A Common Stock	10/28/2024		C		6,500	A	$0	6,500	I	By JRS Investments LLC(6)
Class A Common Stock	10/28/2024		S(2)		3,682(2)	D	$102.0806(7)	2,818	I	By JRS Investments LLC(6)
Class A Common Stock	10/28/2024		S(2)		2,522(2)	D	$103.1924(8)	296	I	By JRS Investments LLC(6)
Class A Common Stock	10/28/2024		S(2)		296(2)	D	$103.8409(9)	0	I	By JRS Investments LLC(6)
Class A Common Stock								134,045(10)	D
Class A Common Stock								1,193(11)	I	By wife

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Class B Common Stock	$0	10/28/2024		C			6,500	(12)	(12)	Class A Common Stock	6,500	$0	10,247,610	I	By James R. Scapa Declaration of Trust dated March 5, 1987(1)
Class B Common Stock	$0	10/28/2024		C			6,500	(12)	(12)	Class A Common Stock	6,500	$0	6,633,182	I	By JRS Investments LLC(6)

Explanation of Responses:

1. 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.

2. 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, 2024.

3. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $101.6036 to $102.58 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.

4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $102.65 to $103.61 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.

5. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $103.6750 to $104.305 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.

6. Reporting person serves as Manager. 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.

7. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $101.6036 to $102.58 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.

8. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $102.65 to $103.61 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.

9. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $103.6750 to $104.305 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.

10. Includes 88,194 Class A Common Stock restricted stock units that are unvested.

11. Includes 20 Class A Common Stock restricted stock units that are unvested.

12. 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.

	/s/ Raoul Maitra, attorney-in-fact for James R. Scapa	10/29/2024
	** 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 4 (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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