Penumbra (PEN) officer details insider tax-withholding transaction on RSU vesting

Rhea-AI Filing Summary

Penumbra’s chief accounting officer, Lambert Shiu, reported an insider transaction involving 300 shares of common stock on 12/15/2025. The 300 shares were withheld by the company to cover tax withholding obligations triggered by the vesting of restricted stock units previously granted to him.

After this transaction, Shiu beneficially owns 35,285 Penumbra common shares directly, with a portion of these shares still subject to vesting and including 20 shares purchased under the company’s Employee Stock Purchase Plan on November 19, 2025. He also indirectly owns 300 shares held in his spouse’s IRA.

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^*

Shiu Lambert

(Last) (First) (Middle)

ONE PENUMBRA PLACE

(Street)

ALAMEDA CA 94502

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Penumbra Inc [ PEN ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
12/15/2025

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	12/15/2025		F(1)		300	D	$309.15	35,285(2)(3)	D
Common Stock								300	I	By Spouse's IRA(4)

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 were withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting of restricted stock units granted to the Reporting Person.

2. A portion of these shares is subject to vesting.

3. Includes 20 shares purchased by the Reporting Person under the Issuer's Employee Stock Purchase Plan on November 19, 2025.

4. Shares are held by the Reporting Person's spouse in an IRA.

Remarks:

	/s/ Johanna Roberts, as attorney-in-fact for Lambert Shiu	12/17/2025
	** 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 insider transaction did Penumbra (PEN) report on 12/15/2025?

Penumbra reported that officer Lambert Shiu had 300 shares of common stock withheld on 12/15/2025 to satisfy tax withholding obligations related to vesting restricted stock units.

Who is the reporting person in this Penumbra (PEN) insider report and what is their role?

The reporting person is Lambert Shiu, who serves as Penumbra’s Chief Accounting Officer and is listed as an officer of the company.

How many Penumbra (PEN) shares does Lambert Shiu own after the reported transaction?

Following the transaction, Lambert Shiu beneficially owns 35,285 Penumbra common shares directly and 300 shares indirectly through his spouse’s IRA.

What does transaction code "F" indicate in this Penumbra (PEN) insider report?

Transaction code "F" indicates that shares were withheld by Penumbra to satisfy tax withholding obligations in connection with the vesting of restricted stock units granted to Lambert Shiu.

Are any of Lambert Shiu’s Penumbra (PEN) shares still subject to vesting?

Yes. The filing notes that a portion of the 35,285 directly held shares is subject to vesting.

How many Penumbra (PEN) shares did Lambert Shiu acquire through the Employee Stock Purchase Plan?

The report states that his holdings include 20 shares purchased under Penumbra’s Employee Stock Purchase Plan on November 19, 2025.