// company-profile
Amentum Holdings, Inc.
AMTMExchangeNYSESectorServices-Business Services, NECInc.DEFilings81Insiders37
// api This Amentum Holdings, Inc. insider-trading data is served live by the Form4API insider trading API. Get the same data via API.
// activity-summary
No insider transactions in the last 30 days.
// 90-day insight
Over the last 90 days, Amentum Holdings, Inc. insiders bought $0 (10 transactions) and sold $525K (5 transactions).
- Most active insider: Heller John E. with 3 transactions totaling $204K.
- Largest single sale: $204K by Heller John E. on May 6, 2026.
Activity skews bullish — buys outpace sales.
Institutional Ownership
Top 13F-HR holders of Amentum Holdings, Inc. as of 2026-03-31
Total reported AUM
$4.99B
QoQ change
-0.1%
Reporting period
2026-03-31
#1
AMERICAN SECURITIES LLC
CIK 1475483
$1.17B
45.0M shares
#2
BlackRock, Inc.
CIK 2012383
$329.6M
12.6M shares
#3
PRIMECAP MANAGEMENT CO/CA/
CIK 763212
$315.2M
12.1M shares
Data source: SEC Form 13F-HR filings. Joined with insider activity above — see who's loading up institutionally while insiders are trading. Full 13F-HR API →
Insider Transactions
Sourced from SEC EDGAR Form 4 filings. Updated hourly.
| Date | Insider | Company | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| May 6, 2026 | Mullen Sean Thomas | AMTM | Tax Withholding | 2,762 | $24.89 | $69K |
| May 6, 2026 | Johnson Travis Barton | AMTM | Option Exercise | 13,609 | — | — |
| May 6, 2026 | Mullen Sean Thomas | AMTM | Option Exercise | 9,072 | $0.00 | $0K |
| May 6, 2026 | Arnette Stephen A | AMTM | Tax Withholding | 3,314 | $24.89 | $82K |
| May 6, 2026 | Bruning Jill L | AMTM | Option Exercise | 9,072 | — | — |
45 more transactions hidden
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