Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionGrove Bank & Trust
Latest Disclosed Ownership14,808 shares
Latest Disclosed Value $ 1,781,255
Grove Bank & Trust reports 0.37% decrease in ownership of MRK / Merck & Co., Inc.

On April 8, 2026 - Grove Bank & Trust filed a 13F-HR form disclosing ownership of 14,808 shares of Merck & Co., Inc. (MX:MRK) valued at $1,781,255 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 8, 2026 disclosing 14,863 shares of Merck & Co., Inc.. This represents a change in shares of -0.37% 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)
2026-04-08 2026-03-31 13F MERCK COM 58933Y105 14,808 -55 -0.37 1,781 13.87 0.2014
2026-01-08 2025-12-31 13F MERCK COM 58933Y105 14,863 -136 -0.91 1,564 24.32 0.1760
2025-10-06 2025-09-30 13F MERCK COM 58933Y105 14,999 -596 -3.82 1,259 1.94 0.1473
2025-07-11 2025-06-30 13F MERCK COM 58933Y105 15,595 -1,502 -8.79 1,234 -19.56 0.1540
2025-04-17 2025-03-31 13F MERCK COM 58933Y105 17,097 1,809 11.83 1,535 0.92 0.2051
2025-01-16 2024-12-31 13F Merck COM 58933Y105 15,288 812 5.61 1,521 -7.49 0.2111
2024-10-11 2024-09-30 13F Merck COM 58933Y105 14,476 178 1.24 1,644 -7.18 0.2428
2024-07-24 2024-06-30 13F Merck COM 58933Y105 14,298 353 2.53 1,770 -3.80 0.2841
2024-04-30 2024-03-31 13F Merck COM 58933Y105 13,945 -47 -0.34 1,840 20.66 0.3100
2024-01-30 2023-12-31 13F Merck COM 58933Y105 13,992 -826 -5.57 1,525 0.00 0.2806
2023-10-30 2023-09-30 13F Merck COM 58933Y105 14,818 -378 -2.49 1,526 -13.01 0.3109
2023-07-27 2023-06-30 13F Merck COM 58933Y105 15,196 4 0.03 1,753 8.48 0.3541
2023-05-10 2023-03-31 13F Merck COM 58933Y105 15,192 -3,413 -18.34 1,616 80,700.00 0.3417
2023-02-03 2022-12-31 13F Merck COM 58933Y105 18,605 -11,715 -38.64 2 -99.92 0.4554
2022-10-28 2022-09-30 13F MERCK COMMON STOCK 58933Y105 30,320 79 0.26 2,611 -5.33 0.6470
2022-07-29 2022-06-30 13F MERCK COMMON STOCK 58933Y105 30,241 -1,394 -4.41 2,758 6.24 0.6604
2022-04-22 2022-03-31 13F MERCK COMMON STOCK 58933Y105 31,635 -121 -0.38 2,596 6.66 0.5106
2022-01-31 2021-12-31 13F MERCK COMMON STOCK 58933Y105 31,756 996 3.24 2,434 5.37 0.4648
2021-10-28 2021-09-30 13F MERCK COMMON STOCK 58933Y105 30,760 1,265 4.29 2,310 0.70 0.4860
2021-07-28 2021-06-30 13F MERCK COMMON STOCK 58933Y105 29,495 1,165 4.11 2,294 5.04 0.4968
2021-04-23 2021-03-31 13F MERCK COMMON STOCK 58933Y105 28,330 252 0.90 2,184 -4.88 0.5137
2021-02-03 2020-12-31 13F MERCK COMMON STOCK 58933Y105 28,078 2,181 8.42 2,296 6.89 0.5963
2020-10-30 2020-09-30 13F MERCK COMMON STOCK 58933Y105 25,897 -603 -2.28 2,148 4.83 0.6579
2020-07-31 2020-06-30 13F MERCK COMMON STOCK 58933Y105 26,500 2,218 9.13 2,049 9.69 0.6748
2020-05-05 2020-03-31 13F MERCK COMMON STOCK 58933Y105 24,282 -769 -3.07 1,868 -18.00 0.7373
2020-02-11 2019-12-31 13F MERCK COMMON STOCK 58933Y105 25,051 -1,132 -4.32 2,278 3.36 0.6845
2019-10-30 2019-09-30 13F MERCK COMMON STOCK 58933Y105 26,183 1,744 7.14 2,204 7.56 0.7105
2019-07-24 2019-06-30 13F MERCK COMMON STOCK 58933Y105 24,439 -1,818 -6.92 2,049 -6.18 0.7487
2019-04-26 2019-03-31 13F MERCK COMMON STOCK 58933Y105 26,257 -597 -2.22 2,184 6.43 0.8381
2019-02-13 2018-12-31 13F MERCK COMMON STOCK 58933Y105 26,854 -2,732 -9.23 2,052 -2.24 0.9575
2018-11-07 2018-09-30 13F MERCK COMMON STOCK 58933Y105 29,586 -2,702 -8.37 2,099 7.15 0.8617
2018-08-03 2018-06-30 13F MERCK COMMON STOCK 58933Y105 32,288 -1,718 -5.05 1,959 5.78 0.8349
2018-05-07 2018-03-31 13F MERCK COMMON STOCK 58933Y105 34,006 105 0.31 1,852 -2.94 0.8196
2018-02-02 2017-12-31 13F MERCK COMMON STOCK 58933Y105 33,901 506 1.52 1,908 -10.76 0.8328
2017-11-13 2017-09-30 13F MERCK & CO INC COMMON STOCK 58933Y105 33,395 480 1.46 2,138 1.38 1.0398
2017-07-28 2017-06-30 13F MERCK & CO INC COMMON STOCK 58933Y105 32,915 4,680 16.58 2,109 17.56 1.3491
2017-04-28 2017-03-31 13F MERCK & CO INC COMMON STOCK 58933Y105 28,235 -4,192 -12.93 1,794 -5.97 1.4726
2017-02-03 2016-12-31 13F MERCK & CO INC COMMON STOCK 58933Y105 32,427 3,631 12.61 1,908 6.18 1.4569
2016-11-04 2016-09-30 13F MERCK & CO INC COMMON STOCK 58933Y105 28,796 1,160 4.20 1,797 12.88 1.5310
2016-08-05 2016-06-30 13F MERCK & CO INC COMMON STOCK 58933Y105 27,636 856 3.20 1,592 12.43 1.4263
2016-05-11 2016-03-31 13F MERCK & CO INC COMMON STOCK 58933Y105 26,780 492 1.87 1,416 1.94 1.2903
2016-01-27 2015-12-31 13F MERCK & CO INC COMMON STOCK 58933Y105 26,288 26,288 1,389 1.2452
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.