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

Rhea-AI Filing Summary

Gary K. Lee, Chief Scientific Officer of Lyell Immunopharma (LYEL), reported two routine sales of common stock on 08/11/2025 and 08/12/2025 to satisfy tax withholding obligations from vested restricted stock units. On 08/11/2025 he sold 131 shares at a weighted average price of $10.526 (range $10.045–$11.00), leaving 9,093 shares beneficially owned. On 08/12/2025 he sold 136 shares at a weighted average price of $10.338 (range $10.120–$10.415), leaving 8,957 shares beneficially owned. The Form 4 notes a 1-for-20 reverse stock split effective May 30, 2025 and inclusion of 390 ESPP shares acquired May 18, 2025. The filing was signed by an attorney-in-fact on 08/13/2025.

Positive

• Transactions were disclosed promptly on Form 4 with dates and weighted average prices
• Sales were automatic to cover tax withholding from vested restricted stock units, as stated in the filing
• Filing notes reverse split and ESPP inclusion, improving clarity of reported share counts

Negative

• Reporting person sold a total of 267 shares across two days, reducing direct holdings to 8,957 shares
• Sale price ranges are broad and the filing states specific per-price quantities will be provided only upon request

Insights

Securities Analyst

TL;DR: Insider executed routine sales to cover tax withholding; total of 267 shares sold at weighted averages near $10.43, leaving 8,957 shares.

The Form 4 documents two sales coded as S on 08/11/2025 and 08/12/2025 totaling 267 shares sold to satisfy tax withholding from vested restricted stock units. Weighted average prices reported were $10.526 and $10.338, with price ranges disclosed for each day. Reported beneficial ownership after the transactions is 8,957 shares (direct). The filing also discloses a 1-for-20 reverse split adjustment and inclusion of 390 ESPP shares; these disclosures aid comparability of reported amounts.

Corporate Governance Expert

TL;DR: Disclosure is standard and appears compliant; sales were automatic for tax withholding and the Form 4 was executed by an attorney-in-fact.

The report identifies the reporting person as Chief Scientific Officer and characterizes both transactions as automatic sales to cover tax withholding on vested RSUs. The filing includes explanatory notes on weighted average sale prices and the issuer's recent 1-for-20 reverse stock split, and it was signed by an attorney-in-fact on 08/13/2025. The level of disclosure is consistent with typical insider tax-withholding dispositions.

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
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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^*

Lee Gary K.

(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 Scientific Officer

3. Date of Earliest Transaction (Month/Day/Year)
08/11/2025

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	08/11/2025		S		131(1)	D	$10.526(2)	9,093(3)(4)	D
Common Stock	08/12/2025		S		136(5)	D	$10.338(6)	8,957(7)	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. Shares automatically sold to cover tax withholding obligation from settlement of vested restricted stock units.

2. The price reported above reflects the weighted average price of the shares sold. The sale price ranged from $10.045 to $11.00 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.

3. Includes 390 shares acquired on May 18, 2025 under the Issuer's 2021 Employee Stock Purchase Plan.

4. On May 30, 2025, the Issuer effected a 1-for-20 reverse stock split of its common stock. All share and amounts reported herein reflect the reverse stock split.

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

6. The price reported above reflects the weighted average price of the shares sold. The sale price ranged from $10.120 to $10.415 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.

7. On May 30, 2025, the Issuer effected a 1-for-20 reverse stock split of its common stock. All share and amounts reported herein reflect the reverse stock split.

	/s/ Allison Peth, Attorney-in-Fact	08/13/2025
	** 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).
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FAQ

What insider transactions did Gary K. Lee (LYEL) report on Form 4?

The Form 4 reports two sales: 131 shares on 08/11/2025 and 136 shares on 08/12/2025, totaling 267 shares sold.

Why were the shares sold according to the filing?

The filing states the shares were automatically sold to cover tax withholding obligations from settlement of vested restricted stock units.

What prices were reported for the sales?

Weighted average prices reported were $10.526 for the 08/11 sale (range $10.045–$11.00) and $10.338 for the 08/12 sale (range $10.120–$10.415).

How many shares does Gary K. Lee beneficially own after these transactions?

The filing reports 8,957 shares beneficially owned following the 08/12/2025 transaction.

Does the Form 4 mention any corporate actions affecting share counts?

Yes. The filing discloses a 1-for-20 reverse stock split effective May 30, 2025 and notes that all share amounts reflect that split.

Who signed the Form 4?

The Form 4 was signed by Allison Peth, Attorney-in-Fact on 08/13/2025.