FORM 4
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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).

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, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person *
Thoele Grant Douglas
 2. Issuer Name and Ticker or Trading Symbol
ASPEN AEROGELS INC [ASPN] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
CFO & Treasurer
(Last)
(First)
(Middle)

30 FORBES ROAD, BUILDING B		 3. Date of Earliest Transaction (Month/Day/Year)
10/01/2025
(Street)

NORTHBOROUGH, MA 01532
(City)
(State)
(Zip)
4. If Amendment, Date Original Filed(Month/Day/Year)
10/03/2025		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

10/01/2025 A 10,273 (1) A $ 0 25,392 (2) (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 of Derivative Security: 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


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 5, 2026, an additional one-third of the shares on March 5, 2027 and the remaining one-third of the shares on March 5, 2028.

2.

This Form 4/A is being filed to correct the reported total of Securities Beneficially Owned following the reported transaction. The beneficially owned shares previously reported did not include 10,511 restricted stock units granted prior to the October 1, 2025, transaction date.

3.

Represents 4,608 shares of Common Stock and 20,784 RSUs.



Signatures

/s/ Glenn Deegan, Attorney-in-Fact

12/19/2025
** Signature of Reporting PersonDate
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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