Aspen Aerogels (ASPN) CEO receives equity awards and RSU tax share withholding

Rhea-AI Filing Summary

Aspen Aerogels President and CEO Donald R. Young reported equity compensation grants and related tax withholding transactions. On March 4, he acquired 156,716 shares of Common Stock and 212,249 stock options at a grant price of $0.00 per share through awards.

The restricted stock units vest in three equal installments on March 4, 2027, March 4, 2028, and March 4, 2029, and the options follow the same one-third annual vesting schedule. On March 5, 8,618 shares of Common Stock at $3.27 per share were withheld by the company to cover minimum statutory taxes on RSU vesting, leaving him with 642,109 directly held shares, including 430,387 shares of Common Stock and 211,722 RSUs.

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

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Young Donald R

(Last) (First) (Middle)

C/O ASPEN AEROGELS, INC.,

30 FORBES ROAD, BLDG B

(Street)

NORTHBOROUGH MA 01532

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
ASPEN AEROGELS INC [ ASPN ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	President and CEO

3. Date of Earliest Transaction (Month/Day/Year)
03/04/2026

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
Common Stock	03/04/2026		A		156,716(1)	A	$0	650,727	D
Common Stock	03/05/2026		F		8,618(2)	D	$3.27	642,109(3)	D

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
Stock Options (Right to Buy)	$3.35	03/04/2026		A		212,249		(4)	03/04/2036	Common Stock	212,249	$0	212,249	D

Explanation of Responses:

1. Each Restricted Stock Unit ("RSU") represents the right to receive one share of Common Stock upon vesting. The RSUs vest as to one-third of the shares on March 4, 2027, an additional one-third of the shares on March 4, 2028 and the remaining one-third of the shares on March 4, 2029.

2. Shares withheld by Registrant to satisfy the minimum statutory tax withholding requirements on vesting of Restricted Stock Units ("RSUs").

3. Represents 430,387 shares of Common Stock and 211,722 RSUs.

4. The options vest as to one-third of the shares on March 4, 2027, an additional one-third of the shares on March 4, 2028 and the remaining one-third of the shares on March 4, 2029.

	/s/ Glenn Deegan, Attorney-in-Fact	03/06/2026
	** Signature of Reporting Person	Date
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FAQ

What insider transactions did ASPN CEO Donald R. Young report on this Form 4?

Donald R. Young reported equity awards and tax withholding transactions. He received 156,716 shares of Common Stock and 212,249 stock options as grants, and 8,618 shares of Common Stock were withheld to satisfy minimum statutory tax obligations arising from restricted stock unit vesting.

How many Aspen Aerogels (ASPN) shares and RSUs does the CEO hold after these transactions?

After these transactions, Donald R. Young directly holds 642,109 shares. This consists of 430,387 shares of Common Stock and 211,722 restricted stock units, according to the footnote disclosure summarizing his post-transaction equity position in Aspen Aerogels following the reported grants and tax withholding.

What are the vesting terms for the new ASPN restricted stock units granted to the CEO?

Each restricted stock unit represents one share of Common Stock upon vesting. The RSUs vest in three equal installments: one-third on March 4, 2027, another one-third on March 4, 2028, and the remaining one-third on March 4, 2029, subject to continued service conditions.

What are the vesting terms for the new Aspen Aerogels stock options granted to the CEO?

The stock options vest in three equal tranches over three years. One-third of the option shares vest on March 4, 2027, another one-third vest on March 4, 2028, and the final one-third vest on March 4, 2029, aligning with the RSU vesting schedule.

Why were 8,618 Aspen Aerogels shares disposed of in the CEO’s Form 4 filing?

The 8,618 shares of Common Stock were withheld by Aspen Aerogels at $3.27 per share. This withholding satisfied the minimum statutory tax withholding requirements triggered when restricted stock units vested, representing a tax-withholding disposition rather than an open-market sale transaction.

Were Donald R. Young’s new Aspen Aerogels awards open-market purchases?

No, the new holdings were not open-market purchases. The 156,716 Common Stock shares and 212,249 stock options were acquired as equity awards at a grant price of $0.00 per share, categorized as grant or award acquisitions rather than market transactions.