SES Insider Filing: 39,238 Shares Withheld for Taxes; 470,609 RSUs Unvested

Rhea-AI Filing Summary

Xu Kang, Chief Technology Officer and director of SES AI Corporation (SES), reported a Form 4 for a transaction dated 09/03/2025. The filing shows 39,238 shares of Class A common stock were disposed of under code F(1) at an effective price of $1.09 per share; the filing explains these shares were withheld to satisfy tax withholding obligations related to the vesting of restricted stock units and were not sold on the open market. After the transaction, the reporting person beneficially owns 655,052 shares, which includes 470,609 shares underlying RSUs that remain subject to forfeiture until they vest. The Form 4 was signed by an attorney-in-fact on 09/04/2025.

Positive

• Withholding was used to cover tax obligations on vested RSUs rather than an open-market sale, indicating no active liquidation pressure
• Reporting person retains significant beneficial ownership of 655,052 shares after the transaction

Negative

• Large portion of beneficial ownership is unvested — 470,609 shares underlying RSUs are still subject to forfeiture
• Reported disposal reduced beneficial holdings by 39,238 shares, which marginally lowers immediately available insider-owned shares

Insights

Corporate Governance Expert

TL;DR: Insider withheld vested RSU shares to cover taxes rather than selling in the market, retaining significant beneficial ownership but with most RSUs unvested.

The reported disposal is described as tax withholding on vested RSUs rather than an open-market sale, which reduces the risk that the insider is liquidating equity for cash needs. Retaining a total of 655,052 shares signals continued equity alignment with shareholders, however the filing discloses that 470,609 shares are still subject to forfeiture until vesting, indicating that a large portion of reported ownership is not immediately liquid. For governance review, note the clear identification of role (CTO and director) and timely filing by an attorney-in-fact.

Securities Analyst

TL;DR: The transaction is routine tax withholding on RSU vesting; it modestly reduces reported shares while leaving substantial unvested equity.

Code F(1) transactions tied to tax withholding are generally non-economic dispositions and do not signal active market selling; the price per share shown is $1.09. Post-transaction beneficial ownership of 655,052 shares remains sizeable, but with 470,609 shares listed as underlying RSUs subject to forfeiture, the near-term free float attributable to the insider is smaller. This limits immediate liquidity impact on the stock from this filing.

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

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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^*

Xu Kang

(Last) (First) (Middle)

C/O SES AI CORPORATION

35 CABOT RD

(Street)

WOBURN MA 01801

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
SES AI Corp [ SES ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	CHIEF TECHNOLOGY OFFICER

3. Date of Earliest Transaction (Month/Day/Year)
09/03/2025

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	09/03/2025		F(1)		39,238	D	$1.09	655,052(2)	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

Explanation of Responses:

1. Represents shares withheld to cover the Reporting Person's withholding tax obligations in connection with the vesting of restricted stock units ("RSUs"). These shares were not sold by the Reporting Person.

2. Includes 470,609 shares of Class A Common Stock underlying restricted stock units, which are subject to forfeiture until they vest.

	/s/ Kyle Pilkington, Attorney-in-Fact	09/04/2025
	** 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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did Xu Kang report on the SES (SES) Form 4 filed for 09/03/2025?

The Form 4 reports a disposition of 39,238 Class A shares on 09/03/2025 under code F(1) at $1.09 per share; the filing states these shares were withheld to satisfy tax withholding on vested RSUs.

How many shares does the reporting person beneficially own after the transaction?

After the reported transaction, the reporting person beneficially owns 655,052 shares of Class A common stock.

How many of the reporting person’s shares are unvested or subject to forfeiture?

The filing discloses that 470,609 shares are underlying restricted stock units and remain subject to forfeiture until they vest.

Was the 39,238-share disposition an open-market sale?

No; the filing explains the shares were withheld to cover tax obligations related to RSU vesting and were not sold by the reporting person.

What role does the reporting person hold at SES?

The reporting person, Xu Kang, is listed as both a Director and the Chief Technology Officer (CTO) of SES AI Corporation.