[Form 4] Lyell Immunopharma, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Stephen J. Hill, Chief Operating Officer and director of Lyell Immunopharma (LYEL), reported two equity transactions: 8,000 shares of common stock were issued on 08/20/2025 upon vesting of performance-based restricted stock units (4,000 shares vested immediately; 4,000 remain subject to service-through vesting on 08/20/2026). The reporting person then sold 1,004 shares on 08/21/2025 to cover tax withholding at a weighted-average price of $10.544 (sale prices ranged $10.49–$10.64). Share counts reported: 16,849 shares beneficially owned after issuance and 15,845 shares after the tax-withholding sale.

Positive

• Performance criteria achieved for the awarded RSUs, resulting in issuance of 8,000 common shares (4,000 vested immediately).
• Compensation committee certification of performance-based vesting indicates formal governance oversight of equity awards.
• Alignment of incentives preserved by leaving 4,000 performance shares subject to continued service through 08/20/2026.

Negative

• Automatic sale of 1,004 shares to cover tax withholding reduced the reporting person’s beneficial holdings from 16,849 to 15,845 shares.
• No information provided on the number of shares sold at each price within the reported $10.49–$10.64 range without SEC request.

Insights

Financial Analyst

TL;DR: Routine insider vesting and tax-withholding sale; modest share increase then partial divestiture, no material dilution or unusual trading behavior.

The filing documents the vesting of performance-based RSUs and a subsequent automatic sale to satisfy tax obligations. The net change in beneficial ownership is modest (16,849 to 15,845 shares) and the sale price range ($10.49–$10.64) is narrow, indicating routine settlement activity rather than discretionary market timing. No options, derivatives, or large dispositions were reported that would materially affect outstanding share count or signal major insider repositioning.

Corporate Governance Expert

TL;DR: Governance procedures appear standard: performance-based equity vesting certified by compensation committee and automatic tax sale executed.

The disclosure notes the compensation committee certified achievement of performance criteria for the RSUs before issuance, reflecting governance oversight of award payouts. The remaining 4,000 performance shares remain subject to continued service through 08/20/2026, aligning management incentives with future performance. The automatic sale to cover tax withholding is a common administrative step and does not suggest governance or compliance concerns based on the information provided.

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^*

Hill Stephen J.

(Last) (First) (Middle)

C/O LYELL IMMUNOPHARMA, INC.

201 HASKINS WAY

(Street)

SOUTH SAN FRANCISCO CA 94080

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Lyell Immunopharma, Inc. [ LYEL ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Operating Officer

3. Date of Earliest Transaction (Month/Day/Year)
08/20/2025

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
Common Stock	08/20/2025		A		8,000(1)	A	$0	16,849	D
Common Stock	08/21/2025		S		1,004(2)	D	$10.544(3)	15,845	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. Pursuant to performance-based restricted stock units granted to the reporting person on February 9, 2024, 4,000 shares were issued on the Transaction Date upon the achievement of certain performance criteria certified by the compensation committee of the Issuer's board of directors on the Transaction Date and 4,000 shares will be issued on August 20, 2026, subject to the reporting person providing service through such date.

2. Shares automatically sold to cover tax withholding obligation from settlement of vested restricted stock units.

3. The price reported above reflects the weighted average price of the shares sold. The sale price ranged from $10.49 to $10.64 per share. Upon request from the SEC staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price within the range set forth in this Form 4.

	/s/ Charles W. Newton, Attorney-in-Fact	08/22/2025
	** 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 transactions did Stephen J. Hill report for LYEL?

Hill received 8,000 common sharessold 1,004 shares

How many LYEL shares does Hill beneficially own after these transactions?

15,845 shares

What was the sale price for the shares sold to cover taxes?

Weighted-average sale price $10.544$10.49 to $10.64.

Are any of the performance-based shares still subject to vesting conditions?

Yes. 4,000 of the performance-based restricted stock units will be issued on 08/20/2026 subject to continued service through that date.

Was the RSU vesting certified by the company?

Yes. The compensation committee certified the achievement of the performance criteria before issuance of the vested shares.