SES AI Corp (NYSE: SES) RSU vesting triggers 60,452-share tax withholding

Rhea-AI Filing Summary

SES AI Corp’s chief legal officer, Kyle Pilkington, reported a routine tax-related share disposition. On this Form 4, 60,452 shares of Class A Common Stock were withheld at $0.9873 per share to cover withholding tax obligations tied to vesting restricted stock units, and were not sold in the market.

After the withholding, Pilkington directly holds 719,751 Class A shares, including 435,453 shares underlying restricted stock units that remain subject to forfeiture until they vest.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Pilkington Kyle

Role CHIEF LEGAL OFFICER

Type	Security	Shares	Price	Value
Tax Withholding	Class A Common Stock	60,452	$0.9873	$60K

Holdings After Transaction: Class A Common Stock — 719,751 shares (Direct)

Footnotes (1)

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. Includes 435,453 shares of Class A Common Stock underlying RSUs, which are subject to forfeiture until they vest.

Key Figures

Shares withheld for tax: 60,452 shares Withholding reference price: $0.9873 per share Shares held after transaction: 719,751 shares +1 more

4 metrics

Shares withheld for tax 60,452 shares Withheld to cover RSU-related withholding tax obligations

Withholding reference price $0.9873 per share Value used for 60,452 withheld Class A Common Stock shares

Shares held after transaction 719,751 shares Direct Class A Common Stock holdings following tax withholding

Unvested RSU underlying shares 435,453 shares Class A shares underlying RSUs subject to forfeiture until vesting

Key Terms

restricted stock units, withholding tax obligations, Class A Common Stock, tax-withholding disposition

4 terms

restricted stock units financial

"in connection with the vesting of restricted stock units ("RSUs")."

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

withholding tax obligations financial

"Represents shares withheld to cover the Reporting Person's withholding tax obligations"

Class A Common Stock financial

"Includes 435,453 shares of Class A Common Stock underlying RSUs"

Class A common stock is a category of a company’s shares that carries a specific set of ownership rights—most commonly defined voting power and claims on dividends—set out in the company’s charter. For investors it matters because the class determines how much influence you have over corporate decisions, the share’s likely dividend and trading behavior, and how it compares in value to other share classes, like choosing a particular seat with different privileges at the company’s decision-making table.

tax-withholding disposition financial

"transaction_action": "tax-withholding disposition""

A tax-withholding disposition is an event or transaction—such as selling or transferring securities, exercising options, or receiving compensation—that triggers a requirement to hold back part of the payment and remit it to tax authorities. It matters to investors because it reduces the cash they receive immediately and can change the timing and amount of taxable income, like a cashier taking a portion of your sale proceeds to pay taxes before you get the rest.

Form 4 Insider Transactions: What Each Field Means →

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).

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^*

Pilkington Kyle

(Last) (First) (Middle)

C/O SES AI CORPORATION

35 CABOT ROAD

(Street)

WOBURN MASSACHUSETTS 01801

(City) (State) (Zip)

UNITED STATES

(Country)

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 LEGAL OFFICER

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
03/27/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

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	03/27/2026		F(1)		60,452	D	$0.9873	719,751(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 435,453 shares of Class A Common Stock underlying RSUs, which are subject to forfeiture until they vest.

	/s/ Kyle Pilkington	03/31/2026
	** 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.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transaction did SES (SES) report for Kyle Pilkington?

SES AI’s chief legal officer, Kyle Pilkington, reported 60,452 Class A shares withheld to cover tax obligations from vesting restricted stock units. These shares were not sold on the open market and reflect a routine compensation-related tax payment.

Were Kyle Pilkington’s SES (SES) shares sold in the market?

No, the 60,452 SES AI Class A shares were withheld to satisfy Pilkington’s withholding tax obligations on vesting RSUs. The footnote specifies these shares were not sold by the reporting person, indicating no open-market sale occurred in this filing.

How many SES (SES) shares does Kyle Pilkington hold after this Form 4?

After the tax withholding, Pilkington directly holds 719,751 shares of SES AI Class A Common Stock. This total includes both fully vested shares and shares underlying restricted stock units that remain subject to vesting and potential forfeiture conditions.

What role do restricted stock units play in this SES (SES) Form 4?

The Form 4 notes that 60,452 shares were withheld to cover taxes from vesting restricted stock units. It also states that 435,453 Class A shares underlie RSUs that are still subject to forfeiture until they vest, reflecting ongoing equity-based compensation.

Is this SES (SES) insider transaction a routine tax withholding event?

Yes, the transaction is described as a payment of withholding tax obligations by delivering securities. Code F on the Form 4 and the footnote confirm it is a tax-withholding disposition related to RSU vesting, not a discretionary open-market share sale.