JANA Partners Management, LP MRCY — MERCURY SYS INC

Ownership history in JANA Partners Management, LP  ·  10 quarters on record

AI Ownership Summary

JANA Partners Management, LP reported MERCURY SYS INC (MRCY) in 10 quarterly 13F filings from 2023 Q4 through 2025 Q4. Peak portfolio weight reached 22.33% in 2025 Q3. The latest visible filing shows MRCY at 18.84% 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. Older history is available after unlock; the visible window still shows the most recent pattern.

What this MRCY ownership page tells you

This page is designed to answer the real investor question behind a 13F filing: how meaningful was JANA Partners Management, LP's position in MERCURY SYS 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

MRCY was reported at 18.84% of portfolio in the most recent visible filing.

High-water mark
Peak Conviction
22.33% in 2025 Q3

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

Time in book
Holding Window
2023 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.

MRCY stock page JANA Partners Management, LP fund profile JANA Partners Management, LP full holdings
How JANA Partners Management, LP held MRCY — position size vs. price
% of Fund (quarterly)    MRCY price (quarter-end, indexed to 100)    SPY (indexed to 100)    QQQ (indexed to 100)
📋 Quarterly Holdings History 9 quarters  ▾
Quarter Action Sold % After 3M Timing Shares Change Chg % % of Fund Mkt Value Filed Price (Filed)
2025 Q4 REDUCED 16.8% -0.1% ✅ 4,959,481 -1,000,000 -16.8% 18.84% $362.1M 2026-02-14 (Est.) $82.36
2025 Q3 REDUCED 11.8% -3.2% ✅ 5,959,481 -793,932 -11.8% 22.33% $461.3M 2025-11-14 $70.85
2025 Q2 REDUCED — — — 6,753,413 -188,152 -2.7% 18.27% $363.7M 2025-08-14 $66.83
2025 Q1 UNCHANGED — — — 6,941,565 — 0% 15.45% $299.1M 2025-05-15 $45.87
2024 Q4 UNCHANGED — — — 6,941,565 — 0% 14.34% $291.5M 2025-02-14 $44.45
2024 Q3 ADDED — — — 6,941,565 +16,669 +0.2% 13.33% $256.8M 2024-11-14 $40.84
2024 Q2 UNCHANGED — — — 6,924,896 — 0% 10.93% $186.9M 2024-08-14 $40.00
2024 Q1 ADDED — — — 6,924,896 +1,713,761 +32.9% 11.17% $204.3M 2024-05-15 $29.71
2023 Q4 ADDED — — — 5,211,135 +505,886 +10.8% 12.30% $190.6M 2024-02-14 $30.55
1 older quarter hidden  —  Sign in free or upgrade to Premium to see full history

🏢 Other funds also holding MRCY

As of 2026 Q1 — sorted by position size

Conestoga Capital Advisors, LLC 3Y 7Y 2.79% Bouvel Investment Partners, LLC 3Y 0.69% Corecam Pte. Ltd. 0.41% PEREGRINE CAPITAL MANAGEMENT LLC 3Y 7Y 0.37% MOODY NATIONAL BANK TRUST DIVISION 3Y 7Y 0.29% Bayforest Capital Ltd 0.08% Hilltop National Bank 0.05% Abel Hall, LLC 0.05% Intrua Financial, LLC 3Y 0.03% Louisiana State Employees Retirement System 3Y 7Y 0.03%

FAQ About JANA Partners Management, LP and MRCY

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

How long has JANA Partners Management, LP reported owning MRCY?

JANA Partners Management, LP reported MRCY across 9 quarterly 13F filings, from 2023 Q4 through 2025 Q4.

What was the largest reported MRCY position in JANA Partners Management, LP's portfolio?

The largest reported portfolio weight for MRCY was 22.33% in 2025 Q3.

What is the latest reported MRCY position on this page?

The most recent filing on this page is 2025 Q4, when JANA Partners Management, LP reported 4,959,481 shares, equal to 18.84% of portfolio, with an estimated market value of $362.1M.

What does the chart on this MRCY ownership page compare?

The chart compares JANA Partners Management, LP's quarterly MRCY 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.

How well did JANA Partners Management, LP time their MRCY position?

Based on 13F filing dates vs. subsequent MRCY price moves, JANA Partners Management, LP correctly timed 2 out of 6 reported position changes (33%). The annualised alpha on MRCY relative to SPY over the holding period was +20.4%.

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