Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionThoroughbred Financial Services, Llc
Latest Disclosed Ownership17,768 shares
Latest Disclosed Value $ 2,137
Thoroughbred Financial Services, Llc reports 9.00% increase in ownership of MRK / Merck & Co., Inc.

On May 12, 2026 - Thoroughbred Financial Services, Llc filed a 13F-HR form disclosing ownership of 17,768 shares of Merck & Co., Inc. (MX:MRK) valued at $2,137 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 10, 2026 disclosing 16,301 shares of Merck & Co., Inc.. This represents a change in shares of 9.00% 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)
2026-05-12 2026-03-31 13F MERCK & CO INC COM Stock 58933Y105 17,768 1,467 9.00 2 100.00 0.1276
2026-02-10 2025-12-31 13F MERCK & CO INC COM Stock 58933Y105 16,301 207 1.29 2 0.00 0.1016
2025-11-10 2025-09-30 13F MERCK & CO INC COM Stock 58933Y105 16,094 -514 -3.09 1 0.00 0.0833
2025-08-08 2025-06-30 13F MERCK COM 58933Y105 16,608 -10,504 -38.74 1 -50.00 0.0918
2025-05-09 2025-03-31 13F MERCK COM 58933Y105 27,112 -3,056 -10.13 2 -33.33 0.1519
2025-02-12 2024-12-31 13F MERCK COM 58933Y105 30,168 -2,743 -8.33 3 0.00 0.1834
2024-11-08 2024-09-30 13F MERCK COM 58933Y105 32,911 -9,228 -21.90 4 -40.00 0.2410
2024-08-08 2024-06-30 13F MERCK COM 58933Y105 42,139 6,291 17.55 5 25.00 0.3490
2024-05-07 2024-03-31 13F MERCK COM 58933Y105 35,848 -564 -1.55 5 33.33 0.4550
2024-02-09 2023-12-31 13F MERCK COM 58933Y105 36,412 3,125 9.39 4 0.00 0.3205
2023-11-08 2023-09-30 13F MERCK COM 58933Y105 33,287 6,606 24.76 3 0.00 0.3360
2023-08-03 2023-06-30 13F MERCK COM 58933Y105 26,681 865 3.35 3 50.00 0.4035
2023-04-24 2023-03-31 13F MERCK COM 58933Y105 25,816 212 0.83 3 0.00 0.4057
2023-02-07 2022-12-31 13F MERCK COM 58933Y105 25,604 372 1.47 3 -99.91 0.4641
2022-10-27 2022-09-30 13F MERCK COM 58933Y105 25,232 124 0.49 2,173 -5.07 0.4139
2022-08-03 2022-06-30 13F MERCK COM 58933Y105 25,108 7,121 39.59 2,289 55.19 0.4216
2022-05-04 2022-03-31 13F MERCK COM 58933Y105 17,987 9,251 105.90 1,475 120.48 0.2411
2022-02-09 2021-12-31 13F MERCK COM 58933Y105 8,736 896 11.43 669 13.78 0.1402
2021-10-27 2021-09-30 13F MERCK COM 58933Y105 7,840 741 10.44 588 6.52 0.1431
2021-07-27 2021-06-30 13F MERCK COM 58933Y105 7,099 63 0.90 552 1.85 0.1382
2021-04-30 2021-03-31 13F MERCK &CO. COM 58933Y105 7,036 767 12.23 542 5.86 0.1506
2021-01-26 2020-12-31 13F MERCK &CO. COM 58933Y105 6,269 48 0.77 512 -0.78 0.1587
2020-10-28 2020-09-30 13F MERCK &CO. COM 58933Y105 6,221 342 5.82 516 13.41 0.1940
2020-07-20 2020-06-30 13F MERCK &CO. COM 58933Y105 5,879 -9,204 -61.02 455 -60.78 0.1893
2020-04-23 2020-03-31 13F MERCK &CO. COM 58933Y105 15,083 945 6.68 1,160 -9.80 0.4132
2020-02-05 2019-12-31 13F MERCK COM 58933Y105 14,138 -348 -2.40 1,286 5.50 0.4281
2019-11-12 2019-09-30 13F MERCK COM 58933Y105 14,486 91 0.63 1,219 0.99 0.4623
2019-07-16 2019-06-30 13F/A-1 MERCK &CO INC Total COM 58933Y105 14,395 971 7.23 1,207 8.15 0.4587
2019-07-16 2019-06-30 13F MERCK &CO INC Total COM 58933Y105 1,207,033 1,193,609 1,207,033
2019-05-07 2019-03-31 13F MERCK COM 58933Y105 13,424 285 2.17 1,116 11.27 0.4607
2019-02-13 2018-12-31 13F MERCK COM 58933Y105 13,139 13,139 1,003 0.4921
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.