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

Rhea-AI Filing Summary

Lyell Immunopharma President and CEO Seely Lynn reported automatic sales of vested restricted stock units to satisfy tax withholding. The Form 4 shows 391 shares sold on 08/11/2025 at a weighted average price of $10.526 (range $10.045–$11.00) and 406 shares sold on 08/12/2025 at a weighted average price of $10.338 (range $10.120–$10.415).

All share amounts reflect a 1-for-20 reverse stock split effected on 05/30/2025. Following the reported transactions, the filing lists direct beneficial ownership of 35,234 shares after the first sale and 34,828 shares after the second; the sales are described as automatic to cover tax withholding on vested RSUs.

Positive

• Sales were automatic to cover tax withholding from vested restricted stock units, indicating non-discretionary disposition.
• Reporting person retained a material direct holding after the transactions (reported as 34,828 shares following the second sale).

Negative

• Director and CEO sold shares (391 and 406 shares reported), reducing direct holdings.
• Sales occurred at varied prices (ranges reported up to $11.00 and down to $10.045), reflecting partial execution across price points.

Insights

Financial Analyst

TL;DR: Routine, non-discretionary insider sales to cover RSU tax withholding; not a material change in ownership.

The transactions are reported as automatic dispositions to satisfy tax withholding from vested restricted stock units, totaling 797 shares across two dates with weighted average sale prices of $10.526 and $10.338. The reporting person remains the company's President and CEO and retains direct holdings reported as 34,828 shares after the second sale. Given the stated purpose (tax withholding) and the modest size of the sales relative to total outstanding shares implied by the filing, these items are routine disclosures rather than strategic liquidity moves. Impact: not impactful to valuation but relevant for transparency.

Corporate Governance Expert

TL;DR: Disclosure appears compliant and routine—automatic RSU withholding sales were reported on Form 4 with required detail.

The Form 4 details automated sales associated with RSU settlement and provides weighted average price ranges and post-transaction beneficial ownership figures. The filing also notes a recent 1-for-20 reverse stock split, and the explanations specify the withheld-share purpose. From a governance and disclosure perspective, the document furnishes the necessary transaction codes, quantities, price ranges, and ownership form (direct), supporting regulatory transparency. Impact: not impactful but procedurally important for compliance.

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^*

Seely Lynn

(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)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	President and CEO

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		391(1)	D	$10.526(2)	35,234(3)	D
Common Stock	08/12/2025		S		406(4)	D	$10.338(5)	34,828(6)	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. 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.

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

5. 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.

6. 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).
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 Lyell (LYEL) insider Seely Lynn disclose on the Form 4?

The Form 4 discloses automatic sales of vested RSUs: 391 shares sold on 08/11/2025 and 406 shares sold on 08/12/2025 to cover tax withholding.

How many total shares were sold and at what prices?

A total of 797 shares were sold. Weighted average prices reported: $10.526 (range $10.045–$11.00) and $10.338 (range $10.120–$10.415).

Why were the shares sold according to the filing?

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

What were Seely Lynn's holdings after the reported transactions?

The filing reports direct beneficial ownership of 35,234 shares after the first sale and 34,828 shares after the second sale.

Did the filing note any stock split that affects reported amounts?

Yes. The filing notes a 1-for-20 reverse stock split effective 05/30/2025, and all share amounts reflect that reverse split.