Amentum Holdings
AMTM
486 hedge funds and large institutions have $5.28B invested in Amentum Holdings in 2026 Q1 according to their latest regulatory filings, with 71 funds opening new positions, 150 increasing their positions, 152 reducing their positions, and 61 closing their positions.
212% more call options, than puts
Call options by funds: $134M | Put options by funds: $43M
16% more first-time investments, than exits
New positions opened: 71 | Existing positions closed: 61
2.86% more ownership
Funds ownership: 83.65% → 86.51% (+2.9%)
1% more funds holding
Funds holding: 483 → 486 (+3)
1% less repeat investments, than reductions
Existing positions increased: 150 | Existing positions reduced: 152
6% less capital invested
Capital invested by funds: $5.64B → $5.28B (-$362M)
10% less funds holding in top 10
Funds holding in top 10: 10 → 9 (-1)
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Dimensional Fund Advisors
Austin,
Texas
|
+$61.3M |
| 2 |
PIP
Permian Investment Partners
Dallas,
Texas
|
+$49.2M |
| 3 |
Toronto Dominion Bank
Toronto, Ontario,
Ontario, Canada
|
+$49.1M |
| 4 |
UBS Group
Zurich,
Switzerland
|
+$47.2M |
| 5 |
Bank of America
Charlotte,
North Carolina
|
+$39.1M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Fidelity Investments
Boston,
Massachusetts
|
-$35.4M |
| 2 |
ECM
ExodusPoint Capital Management
New York
|
-$34.3M |
| 3 |
AQR Capital Management
Greenwich,
Connecticut
|
-$29.6M |
| 4 |
FCM
Frontier Capital Management
Boston,
Massachusetts
|
-$26.4M |
| 5 |
Fidelity International
Hamilton,
Bermuda
|
-$24.4M |
AMTM Hedge Fund Activity: Q1 2026 in Review
486 of the 8,177 institutional investors tracked by Wall St. Rank reported a position in Amentum Holdings (AMTM) for Q1 2026, worth a combined $5.28B — down 6.4% from $5.64B a quarter earlier.
Buyers outnumbered sellers: 71 funds opened new AMTM positions and 61 closed out — a net gain of 10 holders — while 150 added to existing stakes and 152 trimmed.
The largest buyer was Dimensional Fund Advisors, adding an estimated $61.3M. The largest seller was Fidelity Investments, cutting an estimated $35.4M.
- 486 institutional investors held Amentum Holdings (AMTM) as of Q1 2026, up from 483 in Q4 2025.
- Funds reported $5.28B of Amentum Holdings stock for Q1 2026, down 6.4% quarter-over-quarter.
- 71 funds opened new Amentum Holdings positions in Q1 2026 and 61 closed out, a net change of +10 holders.
- The largest Amentum Holdings buyer in Q1 2026 was Dimensional Fund Advisors, an estimated $61.3M added.
- The largest Amentum Holdings seller in Q1 2026 was Fidelity Investments, an estimated $35.4M sold.
Based on aggregated 13F filings for Q1 2026.