Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionPrivate Wealth Partners, LLC
Latest Disclosed Ownership309,338 shares
Latest Disclosed Value $ 37,210,226
Private Wealth Partners, LLC reports 0.79% decrease in ownership of MRK / Merck & Co., Inc.

On April 28, 2026 - Private Wealth Partners, LLC filed a 13F-HR form disclosing ownership of 309,338 shares of Merck & Co., Inc. (MX:MRK) valued at $37,210,226 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 27, 2026 disclosing 311,787 shares of Merck & Co., Inc.. This represents a change in shares of -0.79% 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)
2026-04-28 2026-03-31 13F MERCK COM 58933Y105 309,338 -2,449 -0.79 37,210 13.38 2.8663
2026-01-27 2025-12-31 13F MERCK COM 58933Y105 311,787 -6,512 -2.05 32,819 22.85 2.3257
2025-11-04 2025-09-30 13F MERCK COM 58933Y105 318,299 1,535 0.48 26,715 6.54 1.9048
2025-08-01 2025-06-30 13F MERCK COM 58933Y105 316,764 -13,723 -4.15 25,075 -15.47 1.9554
2025-04-22 2025-03-31 13F MERCK COM 58933Y105 330,487 1,316 0.40 29,665 -9.41 2.4563
2025-02-03 2024-12-31 13F MERCK COM 58933Y105 329,171 38,652 13.30 32,746 -0.75 2.5089
2024-10-29 2024-09-30 13F MERCK COM 58933Y105 290,519 -50,478 -14.80 32,991 -21.85 2.6290
2024-08-08 2024-06-30 13F MERCK COM 58933Y105 340,997 -1,049 -0.31 42,215 -6.46 3.1303
2024-05-09 2024-03-31 13F MERCK COM 58933Y105 342,046 -5,974 -1.72 45,133 18.95 3.6087
2024-02-02 2023-12-31 13F MERCK COM 58933Y105 348,020 1,229 0.35 37,941 6.27 3.2069
2023-11-07 2023-09-30 13F MERCK COM 58933Y105 346,791 -1,500 -0.43 35,702 -11.16 3.4131
2023-08-03 2023-06-30 13F MERCK COM 58933Y105 348,291 -2,660 -0.76 40,189 7.64 3.6947
2023-05-04 2023-03-31 13F MERCK COM 58933Y105 350,951 260 0.07 37,338 -4.04 3.7273
2023-01-25 2022-12-31 13F MERCK COM 58933Y105 350,691 4,928 1.43 38,909 30.67 4.4525
2022-10-27 2022-09-30 13F MERCK COM 58933Y105 345,763 3,312 0.97 29,777 -4.63 3.8049
2022-08-02 2022-06-30 13F MERCK COM 58933Y105 342,451 -18,109 -5.02 31,221 5.53 3.6292
2022-05-02 2022-03-31 13F MERCK COM 58933Y105 360,560 -7,505 -2.04 29,584 4.87 2.6497
2022-02-07 2021-12-31 13F MERCK COM 58933Y105 368,065 13,547 3.82 28,209 5.94 2.3840
2021-11-12 2021-09-30 13F MERCK COM 58933Y105 354,518 44,712 14.43 26,628 10.52 2.4736
2021-08-12 2021-06-30 13F MERCK COM 58933Y105 309,806 16,861 5.76 24,094 6.69 2.2285
2021-05-04 2021-03-31 13F MERCK & CO. COM 58933Y105 292,945 9,383 3.31 22,583 -2.64 2.3915
2021-02-03 2020-12-31 13F MERCK & CO. COM 58933Y105 283,562 -2,313 -0.81 23,195 -2.18 2.5176
2020-10-29 2020-09-30 13F MERCK & CO. COM 58933Y105 285,875 37,671 15.18 23,713 23.54 2.7732
2020-07-31 2020-06-30 13F MERCK & CO. COM 58933Y105 248,204 8,526 3.56 19,194 4.08 2.6300
2020-04-24 2020-03-31 13F MERCK & CO. COM 58933Y105 239,678 -4,405 -1.80 18,441 -16.93 3.1097
2020-01-29 2019-12-31 13F MERCK COM 58933Y105 244,083 1,174 0.48 22,199 8.56 3.0254
2019-11-12 2019-09-30 13F MERCK COM 58933Y105 242,909 1,228 0.51 20,448 0.90 3.1826
2019-08-06 2019-06-30 13F MERCK COM 58933Y105 241,681 -308 -0.13 20,265 0.69 3.1195
2019-05-02 2019-03-31 13F MERCK COM 58933Y105 241,989 4,888 2.06 20,126 11.09 3.3099
2019-02-13 2018-12-31 13F MERCK COM 58933Y105 237,101 5,615 2.43 18,117 10.32 3.5055
2018-10-25 2018-09-30 13F MERCK COM 58933Y105 231,486 -1,029 -0.44 16,422 16.35 2.5049
2018-08-16 2018-06-30 13F/A-1 MERCK COM 58933Y105 232,515 -2,133 -0.91 14,114 10.43 2.3736
2018-08-10 2018-06-30 13F MERCK COM 58933Y105 232,515 -2,133 14,114
2018-05-15 2018-03-31 13F MERCK COM 58933Y105 234,648 -17,242 -6.85 12,781 -9.83 2.2258
2018-02-01 2017-12-31 13F MERCK COM 58933Y105 251,890 10,580 4.38 14,174 -8.26 2.6222
2017-11-06 2017-09-30 13F MERCK COM 58933Y105 241,310 1,834 0.77 15,451 0.67 3.1064
2017-07-26 2017-06-30 13F MERCK COM 58933Y105 239,476 34,674 16.93 15,348 17.94 3.3328
2017-04-19 2017-03-31 13F MERCK COM 58933Y105 204,802 -4,137 -1.98 13,013 5.80 2.8837
2017-01-19 2016-12-31 13F MERCK COM 58933Y105 208,939 908 0.44 12,300 -5.26 2.9209
2016-10-18 2016-09-30 13F MERCK COM 58933Y105 208,031 -1,859 -0.89 12,983 7.37 3.1176
2016-07-27 2016-06-30 13F MERCK COM 58933Y105 209,890 -3,799 -1.78 12,092 6.95 2.9060
2016-04-25 2016-03-31 13F MERCK & CO INC COM 58933Y105 213,689 1,741 0.82 11,306 0.99 2.7171
2016-01-25 2015-12-31 13F MERCK & CO INC COM 58933Y105 211,948 -189 -0.09 11,195 6.85 2.6167
2015-10-26 2015-09-30 13F MERCK & CO INC COM 58933Y105 212,137 -9,688 -4.37 10,477 -17.03 2.6366
2015-07-23 2015-06-30 13F MERCK & CO INC COM 58933Y105 221,825 1,102 0.50 12,628 -0.47 2.8524
2015-04-27 2015-03-31 13F/A-1 MERCK & CO INC COM 58933Y105 220,723 16,640 8.15 12,687 9.47 2.9205
2015-04-22 2015-03-31 13F MERCK & CO INC COM 58933Y105 204,083 11,590
2015-01-23 2014-12-31 13F MERCK & CO INC COM 58933Y105 204,083 -16,786 -7.60 11,590 -11.48 2.7242
2014-10-27 2014-09-30 13F MERCK & CO INC COM 58933Y105 220,869 -3,148 -1.41 13,093 1.03 2.8747
2014-08-05 2014-06-30 13F MERCK & CO INC COM 58933Y105 224,017 2,961 1.34 12,959 3.27 2.8474
2014-04-30 2014-03-31 13F/A-1 MERCK & CO INC COM 58933Y105 221,056 -13,798 -5.88 12,549 6.76 2.9587
2014-04-24 2014-03-31 13F MERCK & CO INC COM 58933Y105 221,056 12,549
2014-01-27 2013-12-31 13F MERCK & CO INC COM 58933Y105 234,854 -6,599 -2.73 11,754 2.25 2.6201
2013-10-28 2013-09-30 13F MERCK & CO INC COM 58933Y105 241,453 -2,349 -0.96 11,495 1.50 2.7230
2013-07-29 2013-06-30 13F MERCK & CO INC COM 58933Y105 243,802 243,802 11,325 2.8240
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.