Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionWest Branch Capital LLC
Latest Disclosed Ownership7,432 shares
Latest Disclosed Value $ 893,996
West Branch Capital LLC reports 42.29% increase in ownership of MRK / Merck & Co., Inc.

On April 14, 2026 - West Branch Capital LLC filed a 13F-HR form disclosing ownership of 7,432 shares of Merck & Co., Inc. (MX:MRK) valued at $893,996 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 16, 2026 disclosing 5,223 shares of Merck & Co., Inc.. This represents a change in shares of 42.29% 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 7,432 2,209 42.29 894 62.66 0.2394
2026-01-16 2025-12-31 13F MERCK COM 58933Y105 5,223 -15,875 -75.24 550 -68.98 0.1417
2025-10-21 2025-09-30 13F MERCK COM 58933Y105 21,098 -3,198 -13.16 1,771 -7.96 0.4646
2025-07-16 2025-06-30 13F MERCK COM 58933Y105 24,296 -720 -2.88 1,923 -14.34 0.5688
2025-04-16 2025-03-31 13F MERCK COM 58933Y105 25,016 3,349 15.46 2,245 4.18 0.7491
2025-01-17 2024-12-31 13F MERCK COM 58933Y105 21,667 1,950 9.89 2,155 -3.75 0.6875
2024-10-18 2024-09-30 13F MERCK COM 58933Y105 19,717 1,013 5.42 2,239 -3.28 0.7741
2024-07-26 2024-06-30 13F MERCK COM 58933Y105 18,704 426 2.33 2,316 -3.98 0.8601
2024-04-24 2024-03-31 13F MERCK COM 58933Y105 18,278 1,065 6.19 2,412 28.52 0.9729
2024-01-19 2023-12-31 13F MERCK COM 58933Y105 17,213 873 5.34 1,877 11.53 0.8822
2023-10-20 2023-09-30 13F MERCK COM 58933Y105 16,340 11 0.07 1,682 -10.72 0.8827
2023-08-07 2023-06-30 13F MERCK COM 58933Y105 16,329 -14 -0.09 1,884 8.40 0.9402
2023-04-20 2023-03-31 13F MERCK COM 58933Y105 16,343 295 1.84 1,739 -2.36 0.9687
2023-01-27 2022-12-31 13F MERCK COM 58933Y105 16,048 10 0.06 1,781 28.89 1.0999
2022-10-19 2022-09-30 13F MERCK COM 58933Y105 16,038 428 2.74 1,381 -2.95 0.8584
2022-07-28 2022-06-30 13F MERCK COM 58933Y105 15,610 -30 -0.19 1,423 10.91 0.8230
2022-05-03 2022-03-31 13F MERCK COM 58933Y105 15,640 -442 -2.75 1,283 4.06 0.6130
2022-01-24 2021-12-31 13F MERCK COM 58933Y105 16,082 471 3.02 1,233 5.12 0.5248
2021-11-09 2021-09-30 13F MERCK COM 58933Y105 15,611 -712 -4.36 1,173 -7.57 0.5644
2021-08-17 2021-06-30 13F MERCK COM 58933Y105 16,323 687 4.39 1,269 5.31 0.6236
2021-05-14 2021-03-31 13F MERCK & CO. COM 58933Y105 15,636 -1,678 -9.69 1,205 -14.90 0.7051
2021-02-08 2020-12-31 13F MERCK & CO. COM 58933Y105 17,314 607 3.63 1,416 2.16 0.8368
2020-10-13 2020-09-30 13F MERCK & CO. COM 58933Y105 16,707 678 4.23 1,386 11.77 0.8844
2020-07-08 2020-06-30 13F MERCK & CO. COM 58933Y105 16,029 3,986 33.10 1,240 33.76 0.8736
2020-04-20 2020-03-31 13F MERCK & CO. COM 58933Y105 12,043 -1,487 -10.99 927 -24.70 0.8854
2020-01-07 2019-12-31 13F MERCK COM 58933Y105 13,530 1,896 16.30 1,231 25.74 0.8573
2019-10-23 2019-09-30 13F Merck COM 58933Y105 11,634 11,634 979 0.7251
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.