Amentum Holdings, Inc.
US ˙ NYSE

SecurityAMTM / Amentum Holdings, Inc.
InstitutionCoreCap Advisors, LLC
Latest Disclosed Ownership351 shares
Latest Disclosed Value $ 9,154
CoreCap Advisors, LLC reports 3.57% decrease in ownership of AMTM / Amentum Holdings, Inc.

On April 7, 2026 - CoreCap Advisors, LLC filed a 13F-HR form disclosing ownership of 351 shares of Amentum Holdings, Inc. (US:AMTM) valued at $9,154 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 13, 2026 disclosing 364 shares of Amentum Holdings, Inc.. This represents a change in shares of -3.57% during the quarter. The current value of the position is $8,175 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date
Effective
Date
Form Security Class ID Avg Price
Paid (Est)
Reported
Shares
ΔShares ΔShares
(%)
Reported
Value
(x1000)
ΔValue
(%)
Alloc
(%)
ΔAlloc ΔAlloc (%) Cost Basis
(x1000)
Unrealized
Gain/Loss
(x1000)
2026-04-07 2026-03-31 13F AMENTUM HOLDINGS INC COM Stock 023939101 351 -13 -3.57 9 -10.00 0.0003
2026-01-13 2025-12-31 13F AMENTUM HOLDINGS INC COM Stock 023939101 364 56 18.18 11 42.86 0.0004
2025-10-22 2025-09-30 13F AMENTUM HOLDINGS INC COM Stock 023939101 308 -14 -4.35 7 0.00 0.0003
2025-08-14 2025-06-30 13F AMENTUM HOLDINGS INC COM Stock 023939101 322 20 6.62 8 40.00 0.0003
2025-05-09 2025-03-31 13F AMENTUM HOLDINGS COM 023939101 302 -137 -31.21 5 -44.44 0.0002
2025-02-14 2024-12-31 13F AMENTUM HOLDINGS COM 023939101 439 439 9 0.0004
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.