Form 4: Amentum COO Arnette Reports RSU Vesting, Tax Withholding

Amentum Holdings, Inc.'s Chief Operating Officer, Stephen A. Arnette, reported the vesting of restricted stock units and subsequent sale of shares for tax withholding.

Summary

• Stephen A. Arnette, Chief Operating Officer of Amentum Holdings, Inc. (AMTM), reported transactions on March 2, 2026.
• 2,808 shares of AMTM common stock were acquired upon the vesting of restricted stock units.
• 750 shares of AMTM common stock were disposed of at a price of $30.7 per share for tax withholding purposes related to the RSU vesting.
• Following these transactions, Arnette beneficially owns 96,357 shares of AMTM common stock directly.
• The restricted stock units, representing a contingent right to receive one share of common stock each, vested on March 2, 2026.

Sentiment

Score: 6

Explanation: StockSavvy.ai views this as a moderately positive event, reflecting standard executive compensation and increased insider ownership, albeit with a minor reduction due to tax sales.

Positives

• The vesting of restricted stock units indicates a compensation event for the Chief Operating Officer, aligning management's interests with shareholder value.
• The acquisition of 2,808 shares through RSU vesting increases the COO's direct ownership in the company.

Negatives

• The disposition of 750 shares, while for tax withholding, represents a reduction in the COO's overall share count from the gross vested amount.

Industry Context

StockSavvy.ai notes that routine insider transactions like RSU vesting and tax-related sales are common across industries and typically do not signal significant shifts in company strategy or performance, but rather reflect standard executive compensation practices.

Comparison to Industry Standards

• StockSavvy.ai observes that the practice of executives receiving restricted stock units as part of their compensation package and subsequently selling a portion to cover tax obligations upon vesting is a standard industry practice across publicly traded companies, comparable to compensation structures seen at peers in the government services and defense contracting sectors.

Related Party Transactions

• The reported transactions involve an officer of Amentum Holdings, Inc. and the company's common stock, which is a standard related-party compensation event.

Stakeholder Impact

• Shareholders: Increased direct ownership by a key executive can be seen as a positive alignment of interests.
• Employees: Reflects standard executive compensation practices.

Key Dates

Recommendation

The filing details a routine insider transaction involving the vesting of restricted stock units and a subsequent sale for tax withholding. These transactions are standard executive compensation events and do not provide new fundamental information about the company's operational performance or strategic direction that would warrant a change in investment recommendation. Therefore, a 'hold' recommendation is appropriate as the filing does not present a compelling reason to alter an existing position.

Keywords

Amentum Holdings, AMTM, Stephen A. Arnette, Chief Operating Officer, COO, SEC Form 4, Insider Trading, Restricted Stock Units, RSU Vesting, Stock Compensation, Tax Withholding, Beneficial Ownership