Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionSpears Abacus Advisors LLC
Latest Disclosed Ownership798,223 shares
Latest Disclosed Value $ 96,018,245
Spears Abacus Advisors LLC reports 130.74% increase in ownership of MRK / Merck & Co., Inc.

On May 15, 2026 - Spears Abacus Advisors LLC filed a 13F-HR/A form disclosing ownership of 798,223 shares of Merck & Co., Inc. (MX:MRK) valued at $96,018,245 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 345,940 shares of Merck & Co., Inc.. This represents a change in shares of 130.74% 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)
2026-05-15 2026-03-31 13F/A-1 MERCK COM 58933Y105 798,223 452,283 130.74 96,018 163.69 1.8825
2026-05-14 2026-03-31 13F MERCK COM 58933Y105 798,223 452,283 95,881 1.8997
2026-02-17 2025-12-31 13F MERCK COM 58933Y105 345,940 648 0.19 36,414 25.65 0.6812
2025-11-14 2025-09-30 13F MERCK COM 58933Y105 345,292 7,934 2.35 28,980 8.52 0.5466
2025-08-14 2025-06-30 13F MERCK COM 58933Y105 337,358 2,301 0.69 26,705 -11.20 0.5393
2025-05-14 2025-03-31 13F MERCK COM 58933Y105 335,057 7,260 2.21 30,075 -7.77 0.6476
2025-02-12 2024-12-31 13F MERCK COM 58933Y105 327,797 -1,142 -0.35 32,609 -12.70 0.6699
2024-11-12 2024-09-30 13F MERCK COM 58933Y105 328,939 8,936 2.79 37,354 -5.71 0.7352
2024-08-12 2024-06-30 13F MERCK COM 58933Y105 320,003 -6,737 -2.06 39,616 -8.11 0.8219
2024-05-10 2024-03-31 13F MERCK COM 58933Y105 326,740 313,375 2,344.74 43,113 2,859.03 0.8914
2024-02-14 2023-12-31 13F MERCK COM 58933Y105 13,365 496 3.85 1,457 10.05 0.1160
2023-11-21 2023-09-30 13F MERCK COM 58933Y105 12,869 -800 -5.85 1,325 -16.04 0.1136
2023-08-14 2023-06-30 13F MERCK COM 58933Y105 13,669 946 7.44 1,577 16.56 0.1287
2023-05-15 2023-03-31 13F MERCK COM 58933Y105 12,723 290 2.33 1,354 -1.89 0.1212
2023-02-13 2022-12-31 13F MERCK COM 58933Y105 12,433 -200 -1.58 1,379 26.75 0.1315
2022-11-14 2022-09-30 13F MERCK COM 58933Y105 12,633 0 0.00 1,088 -5.56 0.1074
2022-08-08 2022-06-30 13F MERCK COM 58933Y105 12,633 0 0.00 1,152 11.09 0.1038
2022-05-13 2022-03-31 13F MERCK COM 58933Y105 12,633 -6,004 -32.22 1,037 -27.38 0.0770
2022-02-14 2021-12-31 13F MERCK COM 58933Y105 18,637 6,079 48.41 1,428 51.43 0.0963
2021-11-15 2021-09-30 13F MERCK COM 58933Y105 12,558 -300 -2.33 943 -5.70 0.0682
2021-08-09 2021-06-30 13F MERCK COM 58933Y105 12,858 245 1.94 1,000 2.88 0.0718
2021-05-14 2021-03-31 13F MERCK & CO. COM 58933Y105 12,613 -7,300 -36.66 972 -40.33 0.0751
2021-02-12 2020-12-31 13F MERCK & CO. COM 58933Y105 19,913 -5,050 -20.23 1,629 -21.34 0.1361
2020-11-16 2020-09-30 13F MERCK & CO. COM 58933Y105 24,963 0 0.00 2,071 7.31 0.1973
2020-08-12 2020-06-30 13F MERCK & CO. COM 58933Y105 24,963 20 0.08 1,930 0.57 0.2030
2020-05-15 2020-03-31 13F MERCK & CO. COM 58933Y105 24,943 -1,030 -3.97 1,919 -18.76 0.2348
2020-02-14 2019-12-31 13F MERCK COM 58933Y105 25,973 1,277 5.17 2,362 13.61 0.2526
2019-11-14 2019-09-30 13F MERCK COM 58933Y105 24,696 0 0.00 2,079 0.39 0.2411
2019-08-09 2019-06-30 13F MERCK COM 58933Y105 24,696 -2,120 -7.91 2,071 -7.13 0.2433
2019-05-14 2019-03-31 13F MERCK COM 58933Y105 26,816 -300 -1.11 2,230 7.63 0.2845
2019-02-13 2018-12-31 13F MERCK COM 58933Y105 27,116 -117 -0.43 2,072 7.25 0.3040
2018-11-13 2018-09-30 13F MERCK COM 58933Y105 27,233 -44 -0.16 1,932 16.67 0.2308
2018-08-10 2018-06-30 13F MERCK COM 58933Y105 27,277 111 0.41 1,656 11.89 0.2150
2018-05-15 2018-03-31 13F MERCK COM 58933Y105 27,166 0 0.00 1,480 -3.20 0.1925
2018-02-14 2017-12-31 13F MERCK COM 58933Y105 27,166 0 0.00 1,529 -12.08 0.1862
2017-11-13 2017-09-30 13F MERCK COM 58933Y105 27,166 1,080 4.14 1,739 4.01 0.2080
2017-08-11 2017-06-30 13F MERCK COM 58933Y105 26,086 0 0.00 1,672 0.84 0.2078
2017-05-10 2017-03-31 13F MERCK COM 58933Y105 26,086 660 2.60 1,658 10.75 0.2095
2017-02-13 2016-12-31 13F MERCK COM 58933Y105 25,426 110 0.43 1,497 -5.25 0.1922
2016-11-14 2016-09-30 13F MERCK COM 58933Y105 25,316 0 0.00 1,580 8.37 0.1988
2016-08-10 2016-06-30 13F MERCK COM 58933Y105 25,316 -200 -0.78 1,458 8.00 0.1849
2016-05-13 2016-03-31 13F MERCK & CO INC COM 58933Y105 25,516 -10,007 -28.17 1,350 -28.04 0.1648
2016-02-16 2015-12-31 13F MERCK & CO INC COM 58933Y105 35,523 5,967 20.19 1,876 28.49 0.2146
2015-11-13 2015-09-30 13F MERCK & CO INC COM 58933Y105 29,556 5,640 23.58 1,460 7.20 0.1669
2015-08-14 2015-06-30 13F MERCK & CO INC COM 58933Y105 23,916 0 0.00 1,362 -0.95 0.1508
2015-05-14 2015-03-31 13F MERCK & CO INC COM 58933Y105 23,916 535 2.29 1,375 3.54 0.1646
2015-02-13 2014-12-31 13F MERCK & CO INC COM 58933Y105 23,381 0 0.00 1,328 -4.18 0.1474
2014-11-14 2014-09-30 13F MERCK & CO INC COM 58933Y105 23,381 272 1.18 1,386 3.66 0.1657
2014-08-14 2014-06-30 13F MERCK & CO INC COM 58933Y105 23,109 0 0.00 1,337 1.91 0.1580
2014-05-13 2014-03-31 13F MERCK & CO INC COM 58933Y105 23,109 0 0.00 1,312 13.40 0.1649
2014-02-14 2013-12-31 13F MERCK & CO INC COM 58933Y105 23,109 0 0.00 1,157 5.18 0.1444
2013-11-14 2013-09-30 13F MERCK & CO INC COM 58933Y105 23,109 0 0.00 1,100 2.52 0.1433
2013-08-14 2013-06-30 13F MERCK & CO INC COM 58933Y105 23,109 23,109 1,073 0.1581
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.