Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionBoston Private Wealth Llc
Latest Disclosed Ownership47,708 shares
Latest Disclosed Value $ 5,738,762
Boston Private Wealth Llc reports 5.49% decrease in ownership of MRK / Merck & Co., Inc.

On April 17, 2026 - Boston Private Wealth Llc filed a 13F-HR form disclosing ownership of 47,708 shares of Merck & Co., Inc. (MX:MRK) valued at $5,738,762 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 4, 2026 disclosing 50,478 shares of Merck & Co., Inc.. This represents a change in shares of -5.49% 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)
2026-04-17 2026-03-31 13F MERCK &CO. INC COM COM 58933Y105 47,708 -2,770 -5.49 5,739 8.00 0.1007
2026-02-04 2025-12-31 13F MERCK &CO. INC COM COM 58933Y105 50,478 -12,631 -20.01 5,313 0.32 0.3133
2025-11-06 2025-09-30 13F MERCK &CO. INC COM COM 58933Y105 63,109 8,023 14.56 5,297 21.47 0.2850
2025-08-14 2025-06-30 13F MERCK &CO. INC COM COM 58933Y105 55,086 -37,097 -40.24 4,361 -47.30 0.2336
2025-05-14 2025-03-31 13F MERCK &CO. INC COM COM 58933Y105 92,183 -14,953 -13.96 8,274 -22.36 0.3400
2025-02-05 2024-12-31 13F MERCK &CO. INC COM COM 58933Y105 107,136 107,136 10,658 0.1991
2024-10-18 2024-09-30 13F MERCK &CO. INC COM COM 58933Y105 0 -115,158 -100.00 0 -100.00
2024-08-06 2024-06-30 13F MERCK &CO. INC COM COM 58933Y105 115,158 -7,028 -5.75 14,257 -11.57 0.3529
2024-05-15 2024-03-31 13F MERCK &CO. INC COM COM 58933Y105 122,186 -5,110 -4.01 16,122 16.18 0.3594
2024-01-30 2023-12-31 13F MERCK &CO. INC COM COM 58933Y105 127,296 -12,226 -8.76 13,878 -3.38 0.3376
2023-10-23 2023-09-30 13F MERCK &CO. INC COM COM 58933Y105 139,522 -10,552 -7.03 14,364 -17.06 0.3155
2023-07-24 2023-06-30 13F MERCK &CO. INC COM COM 58933Y105 150,074 -44,877 -23.02 17,317 -16.50 0.3130
2023-05-12 2023-03-31 13F MERCK &CO. INC COM COM 58933Y105 194,951 -303,501 -60.89 20,741 -62.50 0.2899
2023-02-10 2022-12-31 13F Merck COM 58933Y105 498,452 -29,977 -5.67 55,303 21.52 0.7466
2022-11-09 2022-09-30 13F Merck COM 58933Y105 528,429 28,757 5.76 45,508 -0.10 0.6646
2022-08-16 2022-06-30 13F Merck COM 58933Y105 499,672 2,037 0.41 45,555 11.57 0.7007
2022-05-13 2022-03-31 13F Merck COM 58933Y105 497,635 20,568 4.31 40,831 11.68 0.5468
2022-02-15 2021-12-31 13F Merck COM 58933Y105 477,067 -1,068 -0.22 36,562 1.81 0.5996
2021-11-09 2021-09-30 13F Merck COM 58933Y105 478,135 -6,368 -1.31 35,912 -4.69 0.4614
2021-08-13 2021-06-30 13F Merck COM 58933Y105 484,503 4,828 1.01 37,680 1.90 0.4777
2021-05-11 2021-03-31 13F Merck COM 58933Y105 479,675 581 0.12 36,978 -5.64 0.5151
2021-02-10 2020-12-31 13F MERCK & CO. INC COM COM 58933Y105 479,094 -9,836 -2.01 39,190 -3.37 0.5752
2020-11-10 2020-09-30 13F MERCK & CO. INC COM COM 58933Y105 488,930 -55,168 -10.14 40,557 -3.61 0.6688
2020-08-05 2020-06-30 13F MERCK & CO. INC COM COM 58933Y105 544,098 15,028 2.84 42,075 3.36 0.7820
2020-05-11 2020-03-31 13F Merck COM 58933Y105 529,070 8,939 1.72 40,706 -13.95 0.9881
2020-02-13 2019-12-31 13F Merck COM 58933Y105 520,131 8,327 1.63 47,306 9.80 0.8611
2019-11-01 2019-09-30 13F Merck COM 58933Y105 511,804 -9,433 -1.81 43,084 -1.42 0.8576
2019-07-10 2019-06-30 13F Merck COM 58933Y105 521,237 -27,724 -5.05 43,706 -4.27 1.4680
2019-05-14 2019-03-31 13F Merck COM 58933Y105 548,961 -18,162 -3.20 45,657 5.36 1.8034
2019-02-14 2018-12-31 13F Merck COM 58933Y105 567,123 -16,069 -2.76 43,334 4.74 1.8488
2018-11-13 2018-09-30 13F Merck COM 58933Y105 583,192 5,842 1.01 41,372 18.05 1.4633
2018-08-14 2018-06-30 13F Merck COM 58933Y105 577,350 -27,120 -4.49 35,045 6.44 1.3439
2018-05-11 2018-03-31 13F Merck COM 58933Y105 604,470 -2,240 -0.37 32,926 -3.55 1.2630
2018-02-13 2017-12-31 13F Merck COM 58933Y105 606,710 -40,861 -6.31 34,139 -17.67 1.2843
2017-11-13 2017-09-30 13F Merck COM 58933Y105 647,571 582 0.09 41,464 0.00 1.5946
2017-08-04 2017-06-30 13F Merck COM 58933Y105 646,989 -10,004 -1.52 41,465 -0.67 1.6269
2017-05-11 2017-03-31 13F Merck COM 58933Y105 656,993 -3,814 -0.58 41,746 7.31 1.6629
2017-02-15 2016-12-31 13F Merck COM 58933Y105 660,807 -1,724 -0.26 38,902 -5.92 1.6096
2016-11-15 2016-09-30 13F/A-1 Merck COM 58933Y105 662,531 -6,913 -1.03 41,349 7.21 1.6816
2016-11-14 2016-09-30 13F Merck COM 58933Y105 669,444 0 38,567 1.5735
2016-08-01 2016-06-30 13F Merck COM 58933Y105 669,444 -9,760 -1.44 38,567 7.32 1.5735
2016-05-13 2016-03-31 13F Merck COM 58933Y105 679,204 -4,721 -0.69 35,937 -0.52 1.4632
2016-02-12 2015-12-31 13F Merck COM 58933Y105 683,925 3,711 0.55 36,125 7.53 1.4250
2015-11-12 2015-09-30 13F Merck COM 58933Y105 680,214 339 0.05 33,596 -13.20 1.3023
2015-08-13 2015-06-30 13F Merck COM 58933Y105 679,875 -9,920 -1.44 38,705 -2.38 1.2809
2015-05-12 2015-03-31 13F Merck COM 58933Y105 689,795 5,019 0.73 39,649 1.95 1.2801
2015-02-10 2014-12-31 13F Merck COM 58933Y105 684,776 684,776 38,889 1.2576
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.