Arnette Stephen A 4

What Happened

• Stephen A. Arnette, Chief Operating Officer of Amentum Holdings (AMTM), had 13,609 restricted stock units (RSUs) convert into 13,609 shares of AMTM common stock on 2026-05-06.
• To cover tax withholding on the vesting, 3,314 shares were tendered at $24.89 per share, totaling $82,485. Net shares issued to Arnette were 10,295 (13,609 granted minus 3,314 withheld).
• This was an award/vesting event (not an open-market purchase or a voluntary sale).

Key Details

• Transaction date: 2026-05-06; Form filed: 2026-05-07.
• Reported entries: conversion/exercise of derivative (RSU conversion) for 13,609 shares; tax withholding by tender of 3,314 shares at $24.89 each ($82,485). One transaction line shows $0 exercise price because RSUs convert without a cash exercise price.
• Shares owned after the transaction: not specified in the provided filing.
• Footnotes: F1 = distribution upon RSU vesting; F2 = shares withheld for tax withholding; F3 = each RSU = one share; F4 = typical vesting schedule (one-half vests at 18 months and three years).
• Filing appears timely (no late-filing flag indicated).

Context

• This was a routine RSU vesting and tax-withholding event. The conversion of RSUs into shares is common compensation and does not by itself indicate a buy or sell decision by the insider. Tendering shares for tax withholding is a standard payroll tax practice, not an open-market sale.