Form 4: ALNYLAM CEO Sells Shares for Tax Obligations

Alnylam Pharmaceuticals CEO Yvonne Greenstreet sold 2,933 shares of common stock to cover tax withholding obligations related to vested restricted stock units.

Summary

• Yvonne Greenstreet, Chief Executive Officer and Director of Alnylam Pharmaceuticals, Inc. (ALNY), engaged in multiple transactions.
• On March 4, 2026, Greenstreet sold a total of 2,933 shares of ALNY common stock.
• These sales were executed at weighted average prices ranging from $319.03 to $325.67 per share.
• The sales were mandatory 'sell-to-cover' transactions to satisfy minimum statutory tax withholding obligations upon the vesting of restricted stock units.
• Following these transactions, Greenstreet directly beneficially owns 95,695 shares of common stock.
• Additionally, Greenstreet indirectly acquired 407 shares of ALNY common stock through the issuer's 401(k) plan as a result of the matching contribution program.
• Greenstreet indirectly beneficially owns 407 shares through a managed account (401k plan).

Sentiment

Score: 5

Explanation: StockSavvy.ai views this as a neutral event, as the sales are explicitly for tax purposes related to vested equity, a standard practice for executive compensation.

Positives

• The acquisition of 407 shares through the 401(k) plan indicates continued participation in the company's employee benefits.

Negatives

• The sale of 2,933 shares by a key executive, even if for tax purposes, reduces their direct ownership stake.

Future Outlook

NA

Industry Context

StockSavvy.ai notes that routine 'sell-to-cover' transactions for tax obligations are common among executives receiving equity compensation and typically do not signal a change in management's outlook on the company's prospects. This is a standard practice in the biotechnology and pharmaceutical industry where executive compensation often includes significant equity components.

Stakeholder Impact

• Shareholders: Minor reduction in direct insider ownership, but the 'sell-to-cover' nature suggests no change in fundamental outlook.
• Employees: The 401(k) acquisition highlights ongoing employee benefits and participation in company stock plans.

Key Dates

Recommendation

The filing details routine insider transactions, specifically 'sell-to-cover' sales for tax obligations and a minor 401(k) acquisition. These are standard events for executives with equity compensation and do not indicate a change in the company's fundamental prospects or management's confidence. Therefore, a 'hold' recommendation is appropriate as this filing provides no new information to alter an existing investment thesis.

Keywords

Alnylam Pharmaceuticals, ALNY, Yvonne Greenstreet, Insider Trading, Form 4, Stock Sale, Restricted Stock Units, Tax Withholding, CEO, Director