Mercury Systems, Inc.
US ˙ NasdaqGS ˙ US5893781089

SecurityMRCY / Mercury Systems, Inc.
InstitutionCitadel Advisors Llc
ManagerKen Griffin
Latest Disclosed Ownership292,866 shares
Latest Disclosed Value $ 21,352,860
Citadel Advisors Llc ownership in MRCY / Mercury Systems, Inc.

On May 15, 2026 - Citadel Advisors Llc filed a 13F-HR form disclosing ownership of 292,866 shares of Mercury Systems, Inc. (US:MRCY) valued at $21,352,860 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 104,376 shares of Mercury Systems, Inc.. This represents a change in shares of 180.59% during the quarter. The current value of the position is $32,587,200 USD.

Citadel Advisors Llc has a history of taking positions in derivatives of the underlying security (MRCY) in the form of stock options. The firm currently holds call options representing 49,600 of underlying shares valued at $3,616,336 USD and put options representing 10,500 of underlying shares valued at $765,555 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

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.

Upgrade to unlock premium data and export to Excel .

Institutional Put/Call Ratios
(Premium Subscription Required)

In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

MRCY / Mercury Systems, Inc. Historical Put/Call Ratio
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)
2026-05-15 2026-03-31 13F MERCURY SYS COM 589378108 292,866 188,490 180.59 21,353 180.21 0.0030
2026-02-17 2025-12-31 13F MERCURY SYS COM 589378108 104,376 -46,198 -30.68 7,620 -34.61 0.0011
2025-11-14 2025-09-30 13F MERCURY SYS COM 589378108 150,574 -146,403 -49.30 11,654 -27.14 0.0018
2025-08-14 2025-06-30 13F MERCURY SYS COM 589378108 296,977 107,542 56.77 15,995 95.97 0.0028
2025-05-15 2025-03-31 13F MERCURY SYS COM 589378108 189,435 176,722 1,390.09 8,163 1,431.33 0.0015
2025-02-14 2024-12-31 13F MERCURY SYS COM 589378108 12,713 -51,372 -80.16 534 -77.52 0.0001
2024-11-14 2024-09-30 13F MERCURY SYS COM 589378108 64,085 64,085 2,371 0.0005
2024-08-14 2024-06-30 13F MERCURY SYS COM 589378108 0 -126,321 -100.00 0 -100.00
2024-05-15 2024-03-31 13F MERCURY SYS COM 589378108 126,321 97,506 338.39 3,726 253.85 0.0007
2024-02-14 2023-12-31 13F MERCURY SYS COM 589378108 28,815 -318,989 -91.72 1,054 -91.84 0.0002
2023-11-14 2023-09-30 13F MERCURY SYS COM 589378108 347,804 -174,104 -33.36 12,900 -28.54 0.0028
2023-08-14 2023-06-30 13F MERCURY SYS COM 589378108 521,908 506,378 3,260.64 18,053 2,176.42 0.0037
2023-05-15 2023-03-31 13F MERCURY SYS COM 589378108 15,530 -10,450 -40.22 794 -31.76 0.0002
2023-02-14 2022-12-31 13F MERCURY SYS COM 589378108 25,980 -5,035 -16.23 1,162 -7.70 0.0003
2022-11-14 2022-09-30 13F MERCURY SYS COM 589378108 31,015 26,317 560.17 1,259 316.89 0.0003
2022-08-15 2022-06-30 13F MERCURY SYS COM 589378108 4,698 -85,324 -94.78 302 -94.79 0.0001
2022-05-16 2022-03-31 13F MERCURY SYS COM 589378108 90,022 56,665 169.87 5,802 215.84 0.0012
2022-02-14 2021-12-31 13F MERCURY SYS COM 589378108 33,357 -323,320 -90.65 1,837 -89.14 0.0004
2021-11-15 2021-09-30 13F MERCURY SYS Cmn 589378108 356,677 304,167 579.26 16,913 386.01 0.0035
2021-08-16 2021-06-30 13F MERCURY SYS COM 589378108 52,510 -155,220 -74.72 3,480 -76.29 0.0008
2021-05-21 2021-03-31 13F/A-1 MERCURY SYS COM 589378108 207,730 58,439 39.14 14,676 11.64 0.0036
2021-05-17 2021-03-31 13F MERCURY SYS COM 589378108 207,730 58,439 14,676 0.0036
2021-02-16 2020-12-31 13F MERCURY SYS COM 589378108 149,291 30,494 25.67 13,146 42.86 0.0034
2020-11-16 2020-09-30 13F MERCURY SYS COM 589378108 118,797 8,250 7.46 9,202 5.82 0.0026
2020-08-14 2020-06-30 13F MERCURY SYS Cmn 589378108 110,547 5,983 5.72 8,696 16.57 0.0031
2020-05-15 2020-03-31 13F MERCURY SYS Cmn 589378108 104,564 88,707 559.42 7,460 580.66 0.0034
2020-02-14 2019-12-31 13F MERCURY SYS Cmn 589378108 15,857 -87,968 -84.73 1,096 -84.99 0.0005
2019-08-14 2019-06-30 13F MERCURY SYS Cmn 589378108 103,825 12,254 13.38 7,304 24.47 0.0033
2019-05-15 2019-03-31 13F MERCURY SYS Cmn 589378108 91,571 85,438 1,393.09 5,868 1,923.45 0.0029
2019-02-14 2018-12-31 13F MERCURY SYS Cmn 589378108 6,133 1,169 23.55 290 5.45 0.0002
2018-11-13 2018-09-30 13F MERCURY SYS Cmn 589378108 4,964 -23,425 -82.51 275 -74.56 0.0001
2018-08-14 2018-06-30 13F/A-1 MERCURY SYS Cmn 589378108 28,389 19,005 202.53 1,081 138.63 0.0005
2018-08-10 2018-06-30 13F MERCURY SYS Cmn 589378108 28,389 19,005 1,081
2018-05-14 2018-03-31 13F/A-1 MERCURY SYS Cmn 589378108 9,384 1,366 17.04 453 9.95 0.0002
2018-05-11 2018-03-31 13F MERCURY SYS Cmn 589378108 9,384 1,366 453
2018-02-09 2017-12-31 13F MERCURY SYS Cmn 589378108 8,018 8,018 412 0.0003
2017-02-10 2016-12-31 13F MERCURY SYSTEMS Cmn 589378108 0 -11,419 -100.00 0 -100.00
2017-01-31 2016-09-30 13F/A-1 MERCURY SYS Cmn 589378108 11,419 11,419 0.00 281 0.0003
2016-11-10 2016-09-30 13F MERCURY SYSTEMS Cmn 589378108 11,419 281
2016-08-12 2016-06-30 13F MERCURY SYSTEMS Cmn 589378108 0 -50,318 -100.00 0 -100.00
2017-01-31 2016-03-31 13F/A-1 MERCURY SYS Cmn 589378108 50,318 26,378 110.18 1,021 132.05 0.0013
2016-05-13 2016-03-31 13F MERCURY SYSTEMS Cmn 589378108 50,318 1,021
2017-01-31 2015-12-31 13F/A-1 MERCURY SYS Cmn 589378108 23,940 -23,005 -49.00 440 -41.10 0.0005
2016-02-12 2015-12-31 13F MERCURY SYSTEMS Cmn 589378108 23,940 440
2015-11-16 2015-09-30 13F MERCURY SYSTEMS Cmn 589378108 46,945 11,622 32.90 747 44.49 0.0007
2015-08-14 2015-06-30 13F MERCURY SYSTEMS Cmn 589378108 35,323 -78,132 -68.87 517 -70.69 0.0005
2015-05-15 2015-03-31 13F MERCURY SYSTEMS Cmn 589378108 113,455 38,041 50.44 1,764 68.00 0.0020
2015-02-17 2014-12-31 13F MERCURY SYSTEMS Cmn 589378108 75,414 60,598 409.00 1,050 544.17 0.0013
2014-11-14 2014-09-30 13F MERCURY SYSTEMS Cmn 589378108 14,816 14,816 163 0.0002
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-15 2026-03-31 13F MERCURY SYS COM Call 49,600 10.22 3,616 10.08 n/a n/a n/a
2026-02-17 2025-12-31 13F MERCURY SYS COM Call 45,000 67.29 3,285 57.78 n/a n/a n/a
2025-11-14 2025-09-30 13F MERCURY SYS COM Call 26,900 -37.44 2,082 -10.06 n/a n/a n/a
2025-08-14 2025-06-30 13F MERCURY SYS COM Call 43,000 0.00 2,316 25.00 n/a n/a n/a
2025-05-15 2025-03-31 13F MERCURY SYS COM Call 43,000 -5.91 1,853 -3.49 n/a n/a n/a
2025-02-14 2024-12-31 13F MERCURY SYS COM Call 45,700 -12.79 1,919 -0.98 n/a n/a n/a
2024-11-14 2024-09-30 13F MERCURY SYS COM Call 52,400 81.31 1,939 148.46 n/a n/a n/a
2024-08-14 2024-06-30 13F MERCURY SYS COM Call 28,900 -58.54 780 -62.06 n/a n/a n/a
2024-05-15 2024-03-31 13F MERCURY SYS COM Call 69,700 9.08 2,056 -11.99 n/a n/a n/a
2024-02-14 2023-12-31 13F MERCURY SYS COM Call 63,900 97.22 2,337 94.50 n/a n/a n/a
2023-11-14 2023-09-30 13F MERCURY SYS COM Call 32,400 67.88 1,202 80.06 n/a n/a n/a
2023-08-14 2023-06-30 13F MERCURY SYS COM Call 19,300 16.27 668 -21.34 n/a n/a n/a
2023-05-15 2023-03-31 13F MERCURY SYS COM Call 16,600 -48.77 849 -41.48 n/a n/a n/a
2023-02-14 2022-12-31 13F MERCURY SYS COM Call 32,400 121.92 1,450 144.35 n/a n/a n/a
2022-11-14 2022-09-30 13F MERCURY SYS COM Call 14,600 -21.51 593 -50.46 n/a n/a n/a
2022-08-15 2022-06-30 13F MERCURY SYS COM Call 18,600 78.85 1,197 78.66 n/a n/a n/a
2022-05-16 2022-03-31 13F MERCURY SYS COM Call 10,400 -25.71 670 -13.10 n/a n/a n/a
2022-02-14 2021-12-31 13F MERCURY SYS COM Call 14,000 -19.08 771 -5.98 n/a n/a n/a
2021-11-15 2021-09-30 13F MERCURY SYS Cmn Call 17,300 -14.78 820 -39.03 n/a n/a n/a
2021-08-16 2021-06-30 13F MERCURY SYS COM Call 20,300 -6.02 1,345 -11.86 n/a n/a n/a
2021-05-21 2021-03-31 13F/A MERCURY SYS COM Call 21,600 -25.52 1,526 -40.25 n/a n/a n/a
2021-05-17 2021-03-31 13F MERCURY SYS COM Call 21,600 1,526 n/a n/a n/a
2021-02-16 2020-12-31 13F MERCURY SYS COM Call 29,000 63.84 2,554 86.29 n/a n/a n/a
2020-11-16 2020-09-30 13F MERCURY SYS COM Call 17,700 22.92 1,371 21.01 n/a n/a n/a
2020-08-14 2020-06-30 13F MERCURY SYS Cmn Call 14,400 -18.18 1,133 -9.79 n/a n/a n/a
2020-05-15 2020-03-31 13F MERCURY SYS Cmn Call 17,600 -15.38 1,256 -12.60 n/a n/a n/a
2020-02-14 2019-12-31 13F MERCURY SYS Cmn Call 20,800 -32.47 1,437 -42.52 n/a n/a n/a
2019-11-14 2019-09-30 13F MERCURY SYS Cmn Call 30,800 31.06 2,500 51.24 n/a n/a n/a
2019-08-14 2019-06-30 13F MERCURY SYS Cmn Call 23,500 137.37 1,653 160.73 n/a n/a n/a
2019-05-15 2019-03-31 13F MERCURY SYS Cmn Call 9,900 -6.60 634 26.55 n/a n/a n/a
2019-02-14 2018-12-31 13F MERCURY SYS Cmn Call 10,600 -41.44 501 -49.95 n/a n/a n/a
2018-11-13 2018-09-30 13F MERCURY SYS Cmn Call 18,100 115.48 1,001 212.81 n/a n/a n/a
2018-08-14 2018-06-30 13F/A MERCURY SYS Cmn Call 8,400 320 n/a n/a n/a
2018-08-10 2018-06-30 13F MERCURY SYS Cmn Call 8,400 320 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-15 2026-03-31 13F MERCURY SYS COM Put 10,500 -57.32 766 -57.41 n/a n/a n/a
2026-02-17 2025-12-31 13F MERCURY SYS COM Put 24,600 -12.46 1,796 -17.39 n/a n/a n/a
2025-11-14 2025-09-30 13F MERCURY SYS COM Put 28,100 -18.31 2,175 17.39 n/a n/a n/a
2025-08-14 2025-06-30 13F MERCURY SYS COM Put 34,400 -24.23 1,853 -5.32 n/a n/a n/a
2025-05-15 2025-03-31 13F MERCURY SYS COM Put 45,400 78.04 1,956 82.63 n/a n/a n/a
2025-02-14 2024-12-31 13F MERCURY SYS COM Put 25,500 -24.33 1,071 -14.04 n/a n/a n/a
2024-11-14 2024-09-30 13F MERCURY SYS COM Put 33,700 0.00 1,247 37.07 n/a n/a n/a
2024-08-14 2024-06-30 13F MERCURY SYS COM Put 33,700 -11.55 910 -19.06 n/a n/a n/a
2024-05-15 2024-03-31 13F MERCURY SYS COM Put 38,100 8.24 1,124 -12.74 n/a n/a n/a
2024-02-14 2023-12-31 13F MERCURY SYS COM Put 35,200 -18.14 1,287 -19.26 n/a n/a n/a
2023-11-14 2023-09-30 13F MERCURY SYS COM Put 43,000 64.75 1,595 76.72 n/a n/a n/a
2023-08-14 2023-06-30 13F MERCURY SYS COM Put 26,100 121.19 903 49.59 n/a n/a n/a
2023-05-15 2023-03-31 13F MERCURY SYS COM Put 11,800 136.00 603 170.40 n/a n/a n/a
2023-02-14 2022-12-31 13F MERCURY SYS COM Put 5,000 224 n/a n/a n/a
2022-11-14 2022-09-30 13F MERCURY SYS COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2022-08-15 2022-06-30 13F MERCURY SYS COM Put 18,300 -70.58 1,177 -70.64 n/a n/a n/a
2022-05-16 2022-03-31 13F MERCURY SYS COM Put 62,200 7.43 4,009 25.75 n/a n/a n/a
2022-02-14 2021-12-31 13F MERCURY SYS COM Put 57,900 83.81 3,188 113.39 n/a n/a n/a
2021-11-15 2021-09-30 13F MERCURY SYS Cmn Put 31,500 -22.41 1,494 -44.48 n/a n/a n/a
2021-08-16 2021-06-30 13F MERCURY SYS COM Put 40,600 1.50 2,691 -4.78 n/a n/a n/a
2021-05-21 2021-03-31 13F/A MERCURY SYS COM Put 40,000 61.29 2,826 29.40 n/a n/a n/a
2021-05-17 2021-03-31 13F MERCURY SYS COM Put 40,000 2,826 n/a n/a n/a
2021-02-16 2020-12-31 13F MERCURY SYS COM Put 24,800 -21.77 2,184 -11.04 n/a n/a n/a
2020-11-16 2020-09-30 13F MERCURY SYS COM Put 31,700 48.83 2,455 46.57 n/a n/a n/a
2020-08-14 2020-06-30 13F MERCURY SYS Cmn Put 21,300 66.41 1,675 83.46 n/a n/a n/a
2020-05-15 2020-03-31 13F MERCURY SYS Cmn Put 12,800 58.02 913 63.04 n/a n/a n/a
2020-02-14 2019-12-31 13F MERCURY SYS Cmn Put 8,100 -53.71 560 -60.56 n/a n/a n/a
2019-11-14 2019-09-30 13F MERCURY SYS Cmn Put 17,500 78.57 1,420 106.10 n/a n/a n/a
2019-08-14 2019-06-30 13F MERCURY SYS Cmn Put 9,800 15.29 689 26.42 n/a n/a n/a
2019-05-15 2019-03-31 13F MERCURY SYS Cmn Put 8,500 0.00 545 35.57 n/a n/a n/a
2019-02-14 2018-12-31 13F MERCURY SYS Cmn Put 8,500 -34.11 402 -43.70 n/a n/a n/a
2018-11-13 2018-09-30 13F MERCURY SYS Cmn Put 12,900 86.96 714 171.48 n/a n/a n/a
2018-08-14 2018-06-30 13F/A MERCURY SYS Cmn Put 6,900 16.95 263 -7.72 n/a n/a n/a
2018-08-10 2018-06-30 13F MERCURY SYS Cmn Put 6,900 263 n/a n/a n/a
2018-05-14 2018-03-31 13F/A MERCURY SYS Cmn Put 5,900 285 n/a n/a n/a
2018-05-11 2018-03-31 13F MERCURY SYS Cmn Put 5,900 285 n/a n/a n/a
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.