Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionBaldwin Brothers Inc/ma
Latest Disclosed Ownership17,154 shares
Latest Disclosed Value $ 2,063,455
Baldwin Brothers Inc/ma reports 59.68% decrease in ownership of MRK / Merck & Co., Inc.

On April 14, 2026 - Baldwin Brothers Inc/ma filed a 13F-HR form disclosing ownership of 17,154 shares of Merck & Co., Inc. (MX:MRK) valued at $2,063,455 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 7, 2026 disclosing 42,549 shares of Merck & Co., Inc.. This represents a change in shares of -59.68% 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)
2026-04-14 2026-03-31 13F MERCK COM 58933Y105 17,154 -25,395 -59.68 2,063 -53.93 0.1499
2026-01-07 2025-12-31 13F MERCK COM 58933Y105 42,549 -5,624 -11.67 4,479 10.76 0.2864
2025-10-14 2025-09-30 13F MERCK COM 58933Y105 48,173 -149,889 -75.68 4,043 -74.21 0.2634
2025-07-24 2025-06-30 13F MERCK COM 58933Y105 198,062 -2,488 -1.24 15,679 -12.90 1.0648
2025-04-14 2025-03-31 13F MERCK COM 58933Y105 200,550 3,794 1.93 18,001 -8.03 1.2628
2025-01-22 2024-12-31 13F MERCK COM 58933Y105 196,756 7,636 4.04 19,573 -8.88 1.3518
2024-10-16 2024-09-30 13F MERCK COM 58933Y105 189,120 6,189 3.38 21,480 -5.15 1.4640
2024-07-12 2024-06-30 13F MERCK COM 58933Y105 182,931 -7,719 -4.05 22,647 -9.98 1.7643
2024-04-12 2024-03-31 13F MERCK COM 58933Y105 190,650 -1,921 -1.00 25,156 19.82 1.8948
2024-01-08 2023-12-31 13F MERCK COM 58933Y105 192,571 6,307 3.39 20,994 9.49 1.6493
2023-10-10 2023-09-30 13F MERCK COM 58933Y105 186,264 -3,863 -2.03 19,176 -12.59 1.6501
2023-07-14 2023-06-30 13F MERCK COM 58933Y105 190,127 -48 -0.03 21,939 8.43 1.7995
2023-04-21 2023-03-31 13F MERCK COM 58933Y105 190,175 -2,655 -1.38 20,233 -5.43 1.7634
2023-01-27 2022-12-31 13F MERCK COM 58933Y105 192,830 16,726 9.50 21,394 41.07 1.9403
2022-10-14 2022-09-30 13F MERCK COM 58933Y105 176,104 -2,795 -1.56 15,166 -7.01 2.0967
2022-07-18 2022-06-30 13F MERCK COM 58933Y105 178,899 -196,507 -52.35 16,310 -47.05 2.1148
2022-04-13 2022-03-31 13F MERCK & CO. COM 58933Y105 375,406 190,367 102.88 30,803 117.21 2.5629
2022-01-14 2021-12-31 13F MERCK COM 58933Y105 185,039 999 0.54 14,181 2.58 1.4185
2021-10-27 2021-09-30 13F MERCK COM 58933Y105 184,040 708 0.39 13,824 -3.04 1.5341
2021-07-30 2021-06-30 13F MERCK COM 58933Y105 183,332 -48 -0.03 14,257 0.85 1.5579
2021-04-08 2021-03-31 13F MERCK & CO. COM 58933Y105 183,380 4,590 2.57 14,137 -3.34 1.6792
2021-01-12 2020-12-31 13F MERCK & CO. COM 58933Y105 178,790 -1,197 -0.67 14,625 -2.04 1.8388
2020-10-16 2020-09-30 13F MERCK & CO. COM 58933Y105 179,987 -3,075 -1.68 14,930 5.47 2.0419
2020-07-21 2020-06-30 13F MERCK & CO. COM 58933Y105 183,062 -1,079 -0.59 14,156 -0.08 2.0762
2020-04-15 2020-03-31 13F MERCK & CO. COM 58933Y105 184,141 3,272 1.81 14,168 -13.87 2.4796
2020-01-29 2019-12-31 13F MERCK COM 58933Y105 180,869 -173 -0.10 16,450 7.94 2.2998
2019-10-10 2019-09-30 13F MERCK COMMON 58933Y105 181,042 -133 -0.07 15,240 0.32 2.2942
2019-07-19 2019-06-30 13F MERCK COMMON 58933Y105 181,175 -2,950 -1.60 15,191 -0.80 2.2385
2019-04-24 2019-03-31 13F MERCK COMMON 58933Y105 184,125 -15,746 -7.88 15,314 0.28 2.2809
2019-02-01 2018-12-31 13F MERCK COMMON 58933Y105 199,871 -1,381 -0.69 15,272 6.97 2.5610
2018-10-26 2018-09-30 13F MERCK COMMON 58933Y105 201,252 -29,540 -12.80 14,277 1.91 1.9992
2018-07-24 2018-06-30 13F MERCK COMMON 58933Y105 230,792 -912 -0.39 14,009 11.00 2.1773
2018-04-16 2018-03-31 13F MERCK COMMON 58933Y105 231,704 11,717 5.33 12,621 1.95 2.0416
2018-01-24 2017-12-31 13F MERCK COMMON 58933Y105 219,987 -5,928 -2.62 12,379 -14.42 1.9279
2017-10-26 2017-09-30 13F MERCK COMMON 58933Y105 225,915 115 0.05 14,465 -0.05 2.3257
2017-07-13 2017-06-30 13F MERCK COMMON 58933Y105 225,800 -5,025 -2.18 14,472 -1.33 2.3267
2017-04-17 2017-03-31 13F MERCK COMMON 58933Y105 230,825 27,080 13.29 14,667 22.29 2.4186
2017-01-10 2016-12-31 13F MERCK COMMON 58933Y105 203,745 1,828 0.91 11,994 -4.82 2.1665
2016-11-08 2016-09-30 13F MERCK COMMON 58933Y105 201,917 1,343 0.67 12,602 9.06 2.2865
2016-08-11 2016-06-30 13F MERCK COMMON 58933Y105 200,574 10,525 5.54 11,555 14.92 2.3777
2016-05-12 2016-03-31 13F MERCK COMMON 58933Y105 190,049 28,950 17.97 10,055 18.17 1.8049
2016-02-11 2015-12-31 13F Merck COM 58933Y105 161,099 -10,992 -6.39 8,509 0.11 1.3855
2015-11-12 2015-09-30 13F Merck COM 58933Y105 172,091 575 0.34 8,500 -12.95 1.4332
2015-08-10 2015-06-30 13F Merck COM 58933Y105 171,516 1,730 1.02 9,764 0.05 1.4479
2015-05-11 2015-03-31 13F Merck COM 58933Y105 169,786 31,146 22.47 9,759 23.96 1.4378
2015-02-09 2014-12-31 13F Merck COM 58933Y105 138,640 -1,841 -1.31 7,873 -5.46 1.1385
2014-11-13 2014-09-30 13F Merck COM 58933Y105 140,481 17,341 14.08 8,328 16.90 1.1814
2014-08-08 2014-06-30 13F Merck COM 58933Y105 123,140 2,365 1.96 7,124 3.91 1.0575
2014-05-09 2014-03-31 13F Merck COM 58933Y105 120,775 10,985 10.01 6,856 24.77 1.1007
2014-02-12 2013-12-31 13F Merck COM 58933Y105 109,790 13,210 13.68 5,495 19.51 0.8824
2013-11-12 2013-09-30 13F Merck COM 58933Y105 96,580 5,865 6.47 4,598 9.11 0.8398
2013-08-14 2013-06-30 13F Merck COM 58933Y105 90,715 90,715 4,214 0.8335
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.