Merck & Co., Inc.
US ˙ NYSE ˙ US58933Y1055

SecurityMRK / Merck & Co., Inc.
InstitutionWoodstock Corp
Latest Disclosed Ownership124,502 shares
Latest Disclosed Value $ 14,976,346
Woodstock Corp reports 0.66% increase in ownership of MRK / Merck & Co., Inc.

On April 8, 2026 - Woodstock Corp filed a 13F-HR form disclosing ownership of 124,502 shares of Merck & Co., Inc. (US:MRK) valued at $14,976,346 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 14, 2026 disclosing 123,688 shares of Merck & Co., Inc.. This represents a change in shares of 0.66% during the quarter. The current value of the position is $14,280,379 USD.

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 COMMON STOCK 58933Y105 124,502 814 0.66 14,976 15.03 1.3330
2026-01-14 2025-12-31 13F Merck COMMON STOCK 58933Y105 123,688 198 0.16 13,019 25.62 1.1173
2025-10-07 2025-09-30 13F Merck COMMON STOCK 58933Y105 123,490 -875 -0.70 10,365 5.28 0.8981
2025-07-09 2025-06-30 13F Merck COMMON STOCK 58933Y105 124,365 -1,985 -1.57 9,845 -13.20 0.9048
2025-04-09 2025-03-31 13F Merck COMMON STOCK 58933Y105 126,350 799 0.64 11,341 -9.19 1.1203
2025-01-15 2024-12-31 13F Merck COMMON STOCK 58933Y105 125,551 611 0.49 12,490 -11.97 1.2032
2024-10-11 2024-09-30 13F Merck COMMON STOCK 58933Y105 124,940 -1,993 -1.57 14,188 -9.71 1.3652
2024-07-08 2024-06-30 13F Merck COMMON STOCK 58933Y105 126,933 -447 -0.35 15,714 -6.50 1.5979
2024-04-09 2024-03-31 13F Merck COMMON STOCK 58933Y105 127,380 -210 -0.16 16,808 20.84 1.7399
2024-01-08 2023-12-31 13F Merck COMMON STOCK 58933Y105 127,590 -363 -0.28 13,910 5.60 1.6107
2023-10-10 2023-09-30 13F Merck COMMON STOCK 58933Y105 127,953 -441 -0.34 13,173 -11.09 1.6518
2023-07-07 2023-06-30 13F Merck COMMON STOCK 58933Y105 128,394 -791 -0.61 14,815 7.80 1.7482
2023-04-06 2023-03-31 13F Merck COMMON STOCK 58933Y105 129,185 -20 -0.02 13,744 -4.13 1.7528
2023-01-10 2022-12-31 13F Merck COMMON STOCK 58933Y105 129,205 1,700 1.33 14,335 30.54 1.9053
2022-10-11 2022-09-30 13F Merck COMMON STOCK 58933Y105 127,505 673 0.53 10,981 -5.03 1.6336
2022-07-11 2022-06-30 13F Merck COMMON STOCK 58933Y105 126,832 3,105 2.51 11,563 13.90 1.6049
2022-04-07 2022-03-31 13F Merck COMMON STOCK 58933Y105 123,727 -9,585 -7.19 10,152 -0.64 1.1888
2022-01-07 2021-12-31 13F Merck COMMON STOCK 58933Y105 133,312 7,041 5.58 10,217 7.73 1.0698
2021-10-05 2021-09-30 13F Merck COMMON STOCK 58933Y105 126,271 896 0.71 9,484 -2.73 1.1060
2021-07-06 2021-06-30 13F Merck COMMON STOCK 58933Y105 125,375 -975 -0.77 9,750 0.10 1.1473
2021-04-05 2021-03-31 13F Merck COMMON STOCK 58933Y105 126,350 1,969 1.58 9,740 -4.27 1.2383
2021-01-06 2020-12-31 13F Merck COMMON STOCK 58933Y105 124,381 4,153 3.45 10,174 2.02 1.3618
2020-10-02 2020-09-30 13F Merck COMMON STOCK 58933Y105 120,228 -1,238 -1.02 9,973 6.17 1.6105
2020-07-07 2020-06-30 13F Merck COMMON STOCK 58933Y105 121,466 872 0.72 9,393 1.23 1.6012
2020-04-03 2020-03-31 13F Merck COMMON STOCK 58933Y105 120,594 718 0.60 9,279 -14.89 1.8908
2020-01-13 2019-12-31 13F Merck COMMON STOCK 58933Y105 119,876 -155 -0.13 10,903 7.91 1.7758
2019-10-02 2019-09-30 13F Merck COMMON STOCK 58933Y105 120,031 270 0.23 10,104 0.62 1.7604
2019-07-03 2019-06-30 13F Merck COMMON STOCK 58933Y105 119,761 170 0.14 10,042 0.97 1.7532
2019-04-05 2019-03-31 13F Merck COMMON STOCK 58933Y105 119,591 75 0.06 9,946 8.91 1.7819
2019-01-08 2018-12-31 13F Merck COMMON STOCK 58933Y105 119,516 -2,033 -1.67 9,132 5.90 1.8325
2018-10-03 2018-09-30 13F Merck COMMON STOCK 58933Y105 121,549 -1,250 -1.02 8,623 15.68 1.4574
2018-07-23 2018-06-30 13F Merck COMMON STOCK 58933Y105 122,799 -2,615 -2.09 7,454 9.12 1.3722
2018-04-19 2018-03-31 13F Merck COMMON STOCK 58933Y105 125,414 -532 -0.42 6,831 -3.61 1.2916
2018-01-24 2017-12-31 13F Merck COMMON STOCK 58933Y105 125,946 -426 -0.34 7,087 -12.42 1.3070
2017-10-06 2017-09-30 13F Merck COMMON STOCK 58933Y105 126,372 -5,145 -3.91 8,092 -4.00 1.5426
2017-07-13 2017-06-30 13F Merck COMMON STOCK 58933Y105 131,517 3,890 3.05 8,429 3.95 1.6521
2017-04-05 2017-03-31 13F Merck COMMON STOCK 58933Y105 127,627 -6,275 -4.69 8,109 2.87 1.6344
2017-01-05 2016-12-31 13F Merck COMMON STOCK 58933Y105 133,902 2,865 2.19 7,883 -3.61 1.5980
2016-10-06 2016-09-30 13F Merck COMMON STOCK 58933Y105 131,037 -1,811 -1.36 8,178 6.86 1.6734
2016-08-03 2016-06-30 13F Merck COMMON STOCK 58933Y105 132,848 495 0.37 7,653 9.28 1.5796
2016-05-10 2016-03-31 13F Merck COMMON STOCK 58933Y105 132,353 15,785 13.54 7,003 13.74 1.4732
2016-01-11 2015-12-31 13F MERCK COMMON STOCK 58933Y105 116,568 275 0.24 6,157 7.19 1.3537
2015-10-16 2015-09-30 13F MERCK COMMON STOCK 58933Y105 116,293 -21,371 -15.52 5,744 -26.71 1.3076
2015-07-07 2015-06-30 13F MERCK COMMON STOCK 58933Y105 137,664 1,200 0.88 7,837 -0.09 1.4768
2015-04-09 2015-03-31 13F MERCK COMMON STOCK 58933Y105 136,464 3,094 2.32 7,844 3.56 1.4555
2015-02-13 2014-12-31 13F MERCK COMMON STOCK 58933Y105 133,370 3,500 2.70 7,574 -1.62 1.4069
2014-10-06 2014-09-30 13F MERCK COMMON STOCK 58933Y105 129,870 -7,932 -5.76 7,699 -3.42 1.4812
2014-07-07 2014-06-30 13F MERCK COMMON STOCK 58933Y105 137,802 4,100 3.07 7,972 5.03 1.4126
2014-04-07 2014-03-31 13F MERCK COMMON STOCK 58933Y105 133,702 -1,825 -1.35 7,590 11.90 1.4118
2014-01-13 2013-12-31 13F MERCK COMMON STOCK 58933Y105 135,527 9,150 7.24 6,783 12.73 1.2322
2013-10-07 2013-09-30 13F MERCK COMMON STOCK 58933Y105 126,377 2,145 1.73 6,017 4.26 1.1919
2013-07-09 2013-06-30 13F MERCK COMMON STOCK 58933Y105 124,232 124,232 5,771 1.1794
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.