Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionStoneX Group Inc.
Latest Disclosed Ownership42,922 shares
Latest Disclosed Value $ 5,196,721
StoneX Group Inc. reports 26.38% decrease in ownership of MRK / Merck & Co., Inc.

On May 14, 2026 - StoneX Group Inc. filed a 13F-HR form disclosing ownership of 42,922 shares of Merck & Co., Inc. (MX:MRK) valued at $5,196,721 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 12, 2026 disclosing 58,303 shares of Merck & Co., Inc.. This represents a change in shares of -26.38% during the quarter.

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)
2026-05-14 2026-03-31 13F MERCK COM 58933Y105 42,922 -15,381 -26.38 5,197 -16.02 0.2797
2026-02-12 2025-12-31 13F MERCK COM 58933Y105 58,303 74 0.13 6,187 25.42 0.2685
2025-11-14 2025-09-30 13F MERCK COM 58933Y105 58,229 -2,299 -3.80 4,934 1.94 0.2151
2025-08-13 2025-06-30 13F MERCK COM 58933Y105 60,528 -2,444 -3.88 4,839 -14.94 0.2352
2025-08-13 2025-03-31 13F/A-1 MERCK COM 58933Y105 62,972 3,388 5.69 5,690 -4.58 0.3603
2025-05-15 2025-03-31 13F MERCK COM 58933Y105 62,972 3,388 6 0.3603
2025-08-13 2024-12-31 13F/A-1 MERCK COM 58933Y105 59,584 20,370 51.95 5,963 32.99 0.3806
2025-02-12 2024-12-31 13F MERCK COM 58933Y105 59,045 19,831 6 0.3815
2025-08-13 2024-09-30 13F/A-1 MERCK COM 58933Y105 39,214 1,510 4.00 4,483 -4.54 0.3892
2024-11-12 2024-09-30 13F MERCK COM 58933Y105 39,214 1,510 4 0.3947
2025-08-13 2024-06-30 13F/A-1 MERCK COM 58933Y105 37,704 3,470 10.14 4,697 3.37 0.4519
2024-08-07 2024-06-30 13F MERCK COM 58933Y105 37,699 3,465 5 0.4600
2025-08-13 2024-03-31 13F/A-1 MERCK COM 58933Y105 34,234 3,976 13.14 4,543 36.84 0.4926
2024-05-01 2024-03-31 13F MERCK COM 58933Y105 34,234 3,976 5 0.4966
2025-08-13 2023-12-31 13F/A-1 MERCK COM 58933Y105 30,258 3,683 13.86 3,320 20.55 0.4054
2024-02-12 2023-12-31 13F MERCK COM 58933Y105 30,258 3,683 3 0.4074
2025-08-13 2023-09-30 13F/A-1 MERCK COM 58933Y105 26,575 1,523 6.08 2,754 -5.33 0.3705
2023-11-15 2023-09-30 13F MERCK COM 58933Y105 26,012 960 3 0.3701
2025-08-13 2023-06-30 13F/A-1 MERCK COM 58933Y105 25,052 -3,701 -12.87 2,910 -5.49 0.3700
2023-08-14 2023-06-30 13F MERCK COM 58933Y105 25,052 -3,701 3 0.3753
2025-08-13 2023-03-31 13F/A-1 MERCK COM 58933Y105 28,753 6,937 31.80 3,079 26.35 0.4121
2023-05-11 2023-03-31 13F MERCK COM 58933Y105 27,231 5,415 3 0.3960
2025-08-13 2022-12-31 13F/A-1 MERCK COM 58933Y105 21,816 -221 -1.00 2,437 27.34 1.5716
2023-02-10 2022-12-31 13F MERCK COM 58933Y105 21,816 -221 2 1.6041
2025-08-13 2022-09-30 13F/A-1 MERCK COM 58933Y105 22,037 431 1.99 1,913 -3.58 0.9987
2022-11-08 2022-09-30 13F MERCK COM 58933Y105 22,037 431 1,913 1.0136
2025-08-13 2022-06-30 13F/A-1 MERCK COM 58933Y105 21,606 -217 -0.99 1,985 9.92 0.9606
2022-07-27 2022-06-30 13F MERCK COM 58933Y105 21,606 -217 1,985 1.0151
2025-08-13 2022-03-31 13F/A-4 MERCK COM 58933Y105 21,823 3,652 20.10 1,805 28.47 0.1706
2025-08-13 2021-12-31 13F/A-1 MERCK COM 58933Y105 18,171 6,588 56.88 1,405 60.02 0.1680
2022-02-10 2021-12-31 13F MERCK COM 58933Y105 18,171 6,588 1,405 0.1679
2021-10-20 2021-09-30 13F MERCK COM 58933Y105 11,583 -327 -2.75 878 -6.00 0.1262
2021-08-06 2021-06-30 13F MERCK COM 58933Y105 11,910 869 7.87 934 8.86 0.1385
2021-06-30 2021-03-31 13F/A-1 MERCK & CO. COM 58933Y105 11,041 451 4.26 858 -1.72 0.1541
2021-06-23 2021-03-31 13F MERCK & CO. COM 58933Y105 11,041 451 858 0.1574
2021-02-03 2020-12-31 13F MERCK & CO. COM 58933Y105 10,590 1,335 14.42 873 12.94 0.1920
2020-11-12 2020-09-30 13F MERCK & CO. COM 58933Y105 9,255 1,098 13.46 773 21.54 0.2488
2020-08-12 2020-06-30 13F MERCK & CO. COM 58933Y105 8,157 -218 -2.60 636 -2.00 0.2412
2020-04-30 2020-03-31 13F MERCK & CO. COM 58933Y105 8,375 -372 -4.25 649 -18.98 0.3446
2020-01-24 2019-12-31 13F MERCK COM 58933Y105 8,747 843 10.67 801 19.73 0.3266
2019-11-12 2019-09-30 13F MERCK COM 58933Y105 7,904 1,205 17.99 669 18.41 0.4179
2019-07-17 2019-06-30 13F/A-1 MERCK COM 58933Y105 6,699 137 2.09 565 2.91 0.3630
2019-07-12 2019-06-30 13F MERCK COM 58933Y105 7,000 -6,555 565
2019-04-05 2019-03-31 13F MERCK COM 58933Y105 6,562 698 11.90 549 21.73 0.4180
2019-01-15 2018-12-31 13F MERCK COM 58933Y105 5,864 204 3.60 451 12.19 0.4352
2018-10-03 2018-09-30 13F MERCK C 58933Y105 5,660 281 5.22 402 22.94 0.2984
2018-07-23 2018-06-30 13F MERCK C 58933Y105 5,379 -55 -1.01 327 10.47 0.2817
2018-04-19 2018-03-31 13F MERCK C 58933Y105 5,434 87 1.63 296 -1.66 0.2833
2018-02-09 2017-12-31 13F MERCK C 58933Y105 5,347 -158 -2.87 301 -14.49 0.3141
2017-11-14 2017-09-30 13F/A-1 MERCK C 58933Y105 5,505 -39,953 -87.89 352 -87.92 0.4387
2017-11-13 2017-09-30 13F MERCK C 58933Y105 5,505 353
2017-08-31 2017-06-30 13F MERCK C 58933Y105 45,458 25,873 132.11 2,913 152.65 0.9094
2017-05-09 2017-03-31 13F MERCK C 58933Y105 19,585 -266 -1.34 1,153 -1.37 2.5788
2017-02-13 2016-12-31 13F MERCK Com 58933Y105 19,851 -2,282 -10.31 1,169 -15.35 2.0411
2017-02-13 2016-09-30 13F/A-1 MERCK Com 58933Y105 22,133 22,133 1,381 3.0858
2016-11-15 2016-09-30 13F MERCK Com 58933Y105 26,724 1,668
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.