Stocks › AMTM
Amentum Holdings, Inc.
AMTM·NYSE·
United States·USD
United States·USD$18.51
-0.26 (-1.39%)
Close · Oct 7, 2026 · Close Prices from Tiingo.com
AMTM
Amentum Holdings, Inc. · NYSE
Nasdaq 100S&P 500
Filings
Default90D1Y5YALL
AMTMS&P 500 (rebased)
Congress BuyCongress SellInsider BuyInsider SellForm 1448-K ResultsLobbying
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Daily closes, adjusted for splits and dividends · Close Prices from Tiingo.comHover a marker, every one is a filing · move across the line for the crosshair
Congressional Trades
Recent trades of AMTM by members of U.S. Congress · 1 on record
| Politician | Stock | Type | Filed | Traded | |
|---|---|---|---|---|---|
 William R. KeatingHouse · D · MA |
AMTMAmentum Holdings, Inc. · Stock |
Sale $1,001 - $15,000 |
Nov 6, 2024 | Oct 31, 2024 | Filing ↗ |
Whale Activity
Position changes in AMTM reported for 2026-09-30 by 2 tracked institutional filers
- Increased0
- New0
- Held0
- Decreased1
- Closed0
- No prior filing1
| Filer | Shares | Value | Change |
|---|---|---|---|
| CACTI ASSET MANAGEMENT LLC | 875.1K | $15.9M | — |
| SEGRA CAPITAL MANAGEMENT, LLC | 774.9K | $14.0M | decreased |
KeyVex tracks a curated set of large 13F filers plus the largest positions in recent filings, so this is a sample of institutional activity, not the whole market.
Insider Trading
Net shares bought (+) or sold (−) on the open market by AMTM insiders, by quarter · Form 4
Recent Insider Transactions
90 transactions on record · newest first
| Insider | Type | Shares | Price | Value | Date | |
|---|---|---|---|---|---|---|
| Heller John E.Chief Executive Officer · Director | Tax withholding | −8,184 | $24.89 | $204K | May 6, 2026 | Form 4 ↗ |
| Heller John E.Chief Executive Officer · Director | Option exercise | +18.1K | — | — | May 6, 2026 | Form 4 ↗ |
| Mullen Sean ThomasChief Growth Officer | Tax withholding | −2,762 | $24.89 | $69K | May 6, 2026 | Form 4 ↗ |
| Mullen Sean ThomasChief Growth Officer | Option exercise | +9,072 | — | — | May 6, 2026 | Form 4 ↗ |
| Johnson Travis BartonChief Financial Officer | Tax withholding | −4,097 | $24.89 | $102K | May 6, 2026 | Form 4 ↗ |
| Johnson Travis BartonChief Financial Officer | Option exercise | +13.6K | — | — | May 6, 2026 | Form 4 ↗ |
| Bruning Jill LChief Technology Officer | Tax withholding | −2,731 | $24.89 | $68K | May 6, 2026 | Form 4 ↗ |
| Bruning Jill LChief Technology Officer | Option exercise | +9,072 | — | — | May 6, 2026 | Form 4 ↗ |
| Arnette Stephen AChief Operating Officer | Tax withholding | −3,314 | $24.89 | $82K | May 6, 2026 | Form 4 ↗ |
| Arnette Stephen AChief Operating Officer | Option exercise | +13.6K | — | — | May 6, 2026 | Form 4 ↗ |
| Bruning Jill LChief Technology Officer | Gift | −30.0K | $0.00 | $0 | Mar 4, 2026 | Form 4 ↗ |
| Arnette Stephen AChief Operating Officer | Tax withholding | −750 | $30.70 | $23K | Mar 2, 2026 | Form 4 ↗ |
| Arnette Stephen AChief Operating Officer | Option exercise | +2,808 | — | — | Mar 2, 2026 | Form 4 ↗ |
| St. Mary Michele TChief Legal Officer & GC | Tax withholding | −2,308 | $30.05 | $69K | Feb 17, 2026 | Form 4 ↗ |
| St. Mary Michele TChief Legal Officer & GC | Option exercise | +7,080 | — | — | Feb 17, 2026 | Form 4 ↗ |
| IRELAND SUSAN LESLIEDirector | Grant / award | +5,062 | $0.00 | $0 | Feb 6, 2026 | Form 4 ↗ |
| Rowland Sandra E.Director | Grant / award | +5,062 | $0.00 | $0 | Feb 6, 2026 | Form 4 ↗ |
| Rowland Sandra E.Director | Option exercise | +11.6K | — | — | Feb 6, 2026 | Form 4 ↗ |
| Brooks Vincent KDirector | Grant / award | +5,062 | $0.00 | $0 | Feb 6, 2026 | Form 4 ↗ |
| Brooks Vincent KDirector | Option exercise | +11.6K | — | — | Feb 6, 2026 | Form 4 ↗ |
Fund Holders
Mutual funds and ETFs holding AMTM · SEC Form N-PORT
| Fund | Shares | Value | % of fund | As of |
|---|---|---|---|---|
| iShares Core S&P Small-Cap ETF iShares Trust | 9.3M | $191.7M | 0.17% | Jun 30, 2026 |
| VANGUARD PRIMECAP CORE FUND VANGUARD FENWAY FUNDS | 5.5M | $114.0M | 0.63% | Jun 30, 2026 |
| VANGUARD TOTAL STOCK MARKET INDEX FUND VANGUARD INDEX FUNDS | 4.7M | $96.2M | 0.00% | Jun 30, 2026 |
| Invesco Small Cap Value Fund AIM Sector Funds (Invesco Sector Funds) | 4.2M | $93.8M | 0.84% | Jul 31, 2026 |
| VANGUARD SMALL-CAP INDEX FUND VANGUARD INDEX FUNDS | 3.4M | $69.5M | 0.04% | Jun 30, 2026 |
| Invesco Value Opportunities Fund AIM Sector Funds (Invesco Sector Funds) | 2.9M | $65.4M | 0.72% | Jul 31, 2026 |
| Fidelity Value Fund Fidelity Capital Trust | 2.7M | $59.1M | 0.56% | Jul 31, 2026 |
| VANGUARD CAPITAL OPPORTUNITY FUND VANGUARD HORIZON FUNDS | 2.5M | $51.8M | 0.16% | Jun 30, 2026 |
| VANGUARD SMALL-CAP VALUE INDEX FUND VANGUARD INDEX FUNDS | 2.1M | $44.0M | 0.06% | Jun 30, 2026 |
| PRIMECAP Odyssey Stock Fund PRIMECAP Odyssey Funds | 1.9M | $41.7M | 0.91% | Jul 31, 2026 |
Mutual funds and ETFs whose N-PORT filings list AMTM's shares (CUSIP 023939101), each fund at its latest report since Mar 8, 2026, largest positions first. Bonds, options and short positions are left out.
Activist & Passive Stakes
Schedule 13D / 13G beneficial-ownership filings
- PRIMECAP MANAGEMENT CO/CA/SCHEDULE 13G · passive (13G) · 12.3M shares5.0%
Aug 6, 2026 · ↗ - Invesco Ltd.SCHEDULE 13G/A · passive (13G) · 24.5M shares10.1%
May 7, 2026 · ↗ - Lindsay Goldberg IV - A L.P.SCHEDULE 13D · activist (13D) · 43.9M shares18.0%
Dec 23, 2024 · ↗ - Lindsay Goldberg IV L.P.SCHEDULE 13D · activist (13D) · 43.9M shares18.0%
Dec 23, 2024 · ↗ - Lindsay Goldberg GP V LLCSCHEDULE 13D · activist (13D) · 43.9M shares18.0%
Dec 23, 2024 · ↗ - Lindsay Goldberg GP IV LLCSCHEDULE 13D · activist (13D) · 43.9M shares18.0%
Dec 23, 2024 · ↗ - LG GP Holding V LLCSCHEDULE 13D · activist (13D) · 43.9M shares18.0%
Dec 23, 2024 · ↗ - LG GP Holding IV LLCSCHEDULE 13D · activist (13D) · 43.9M shares18.0%
Dec 23, 2024 · ↗ - Goldberg 2020 LLCSCHEDULE 13D · activist (13D) · 43.9M shares18.0%
Dec 23, 2024 · ↗ - Goldberg 2014 LLCSCHEDULE 13D · activist (13D) · 43.9M shares18.0%
Dec 23, 2024 · ↗
Corporate Lobbying
Estimated quarterly lobbying spending reported under the LDA, filings naming amentum as client
- HARBORPOINT STRATEGIES LLCAMENTUM HOLDINGS, INC. · 2026 Q2 · BUD, DEF$30K
Filing ↗ - MONUMENT ADVOCACYAMENTUM · 2026 Q2 · BUD, DEF$30K
Filing ↗ - AMENTUM HOLDINGS, INC.AMENTUM HOLDINGS, INC. · 2026 Q2 · AER, BUD, DEF, ENV$90K
Filing ↗ - PRASAMAMENTUM HOLDINGS, INC · 2026 Q2 · DEF$10K
Filing ↗ - PRASAMAMENTUM HOLDINGS, INC · 2026 Q1 · DEF—
Filing ↗
Government Contracts
Federal awards to Amentum Holdings, Inc. · USAspending
No federal contract awards found for Amentum Holdings, Inc..
U.S. Patents
Recent USPTO applications naming Amentum Holdings, Inc.
No USPTO patent applications found for Amentum Holdings, Inc..
Annual Financials
From AMTM's 10-K filings · XBRL
No annual XBRL figures on record for AMTM. KeyVex's fundamentals cover about 130 large companies so far.
Stock Splits
Every split and reverse split in the price history
No stock splits in AMTM's price history.
About Amentum Holdings, Inc.
From SEC EDGAR company records
Industry (SIC 7389)Services-Business Services, NEC
SectorIndustrials
HeadquartersCHANTILLY, VA
IncorporatedDE
SEC CIK0002011286 ↗
Former namesAmazon Holdco Inc.