Form 4: Penumbra CAO Sells Shares for Tax Obligations

Penumbra's Chief Accounting Officer, Lambert Shiu, reported the disposition of 300 common stock shares to cover tax withholdings related to restricted stock unit vesting.

Summary

• Lambert Shiu, Chief Accounting Officer of Penumbra Inc. (PEN), reported a transaction on December 15, 2025.
• The transaction involved the disposition of 300 shares of Penumbra Common Stock at a price of $309.15 per share.
• These shares were withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting of restricted stock units granted to Mr. Shiu.
• Following this transaction, Mr. Shiu directly beneficially owns 35,285 shares of Common Stock, a portion of which is subject to vesting.
• The reported direct beneficial ownership also includes 20 shares purchased by Mr. Shiu under Penumbra's Employee Stock Purchase Plan on November 19, 2025.
• Additionally, 300 shares are indirectly beneficially owned by Mr. Shiu through his spouse's IRA.

Sentiment

Score: 5

Explanation: The filing reports a routine, tax-related disposition of shares by an insider, which is a neutral event for the company's operational or financial performance.

Industry Context

This filing is a routine disclosure of an insider transaction and does not provide information relevant to broader industry trends or competitive analysis.

Stakeholder Impact

• Shareholders: Minimal impact as this is a routine, tax-related transaction by an officer, not indicative of a change in company fundamentals or management's confidence.

Key Dates

Keywords

Penumbra Inc, PEN, Form 4, Insider Transaction, Stock Sale, Tax Withholding, Restricted Stock Units, Lambert Shiu, Chief Accounting Officer