AMTM β€” AMENTUM HOLDINGS INC

Ownership history in 683 Capital Management, LLC  Β·  6 quarters on record

AI Ownership Summary

683 Capital Management, LLC reported AMENTUM HOLDINGS INC (AMTM) in 6 quarterly 13F filings from 2024 Q4 through 2025 Q4. Peak portfolio weight reached 2.53% in 2025 Q2. The latest visible filing shows AMTM at 1.05% of the fund.

This page tracks quarterly shares, estimated market value, portfolio weight, filing dates, and disclosure-aligned stock prices directly from SEC EDGAR 13F filings.

What this AMTM ownership page tells you

This page is designed to answer the real investor question behind a 13F filing: how meaningful was 683 Capital Management, LLC's position in AMENTUM HOLDINGS INC, and how did that conviction change over time? You can read the holding window, peak weight, latest reported size, disclosure timing, and quarter-by-quarter changes without piecing the story together from raw SEC rows.

Freshest filing
Latest Reported Filing
2025 Q4

AMTM was reported at 1.05% of portfolio in the most recent visible filing.

High-water mark
Peak Conviction
2.53% in 2025 Q2

Peak weight helps separate a token disclosure from a real conviction holding the fund genuinely cared about.

Time in book
Holding Window
2024 Q4 to 2025 Q4

Longer holding windows often tell a very different story from short-lived tactical trades or one-quarter experiments.

Decision context
Why It Matters
Position size beats headlines

Knowing that a fund owned a stock is useful. Knowing whether it was a 0.20% placeholder or a true high-conviction position is where the signal actually starts.

How 683 Capital Management, LLC held AMTM β€” position size vs. price
% of Fund (quarterly)    AMTM price (quarter-end, indexed to 100)
πŸ“‹ Quarterly Holdings History 6 quarters  β–Ύ
Quarter Action Shares Change Chg % % of Fund Mkt Value Filed Price (Filed)
2025 Q4 REDUCED 835,000 -440,000 -34.5% 1.05% $24.2M 2026-02-14 (Est.) $31.00
2025 Q3 REDUCED 1,275,000 -355,000 -21.8% 1.60% $30.5M 2025-11-14 $22.07
2025 Q2 ADDED 1,630,000 +1,530,000 +1530.0% 2.53% $38.5M 2025-08-14 $25.44
2025 Q1 REDUCED 100,000 -913,000 -90.1% 0.13% $1.8M 2025-05-15 $21.60
2025 Q1 ADDED 1,013,000 +588,000 +138.4% 1.27% $18.4M 2025-05-15 $21.60
2024 Q4 INITIATED 425,000 β€” β€” 0.55% $8.9M 2025-02-14 $19.80

FAQ About 683 Capital Management, LLC and AMTM

These are the practical questions this page is built to answer before you even open the full history table.

How long has 683 Capital Management, LLC reported owning AMTM?

683 Capital Management, LLC reported AMTM across 6 quarterly 13F filings, from 2024 Q4 through 2025 Q4.

What was the largest reported AMTM position in 683 Capital Management, LLC's portfolio?

The largest reported portfolio weight for AMTM was 2.53% in 2025 Q2.

What is the latest reported AMTM position on this page?

The most recent filing on this page is 2025 Q4, when 683 Capital Management, LLC reported 835,000 shares, equal to 1.05% of portfolio, with an estimated market value of $24.2M.

What does the chart on this AMTM ownership page compare?

The chart compares 683 Capital Management, LLC's quarterly AMTM portfolio weight with the stock's indexed share price, so you can see whether the fund was building, trimming, or holding the position as price moved.

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