Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionWestend Capital Management LLC
Latest Disclosed Ownership112,368 shares
Latest Disclosed Value $ 13,516,747
Westend Capital Management LLC reports 0.84% increase in ownership of MRK / Merck & Co., Inc.

On April 14, 2026 - Westend Capital Management LLC filed a 13F-HR form disclosing ownership of 112,368 shares of Merck & Co., Inc. (MX:MRK) valued at $13,516,747 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 15, 2026 disclosing 111,430 shares of Merck & Co., Inc.. This represents a change in shares of 0.84% 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 Stock 58933Y105 112,368 938 0.84 13,517 15.24 4.0573
2026-01-15 2025-12-31 13F MERCK Stock 58933Y105 111,430 107,905 3,061.13 11,729 3,875.93 3.2868
2025-10-17 2025-09-30 13F MERCK Stock 58933Y105 3,525 0 0.00 296 5.73 0.0862
2025-07-14 2025-06-30 13F MERCK Stock 58933Y105 3,525 -1,610 -31.35 279 -39.35 0.0860
2025-04-24 2025-03-31 13F MERCK Stock 58933Y105 5,135 300 6.20 461 -4.17 0.1752
2025-01-15 2024-12-31 13F MERCK Stock 58933Y105 4,835 0 0.00 481 -12.57 0.1428
2024-10-10 2024-09-30 13F MERCK Stock 58933Y105 4,835 104 2.20 549 -9.26 0.1882
2024-07-08 2024-06-30 13F MERCK Stock 58933Y105 4,731 -36 -0.76 605 -3.82 0.2126
2024-04-12 2024-03-31 13F MERCK COM 58933Y105 4,767 -1,031 -17.78 629 73.76 0.2439
2016-11-14 2016-09-30 13F MERCK COM 58933Y105 5,798 -725 -11.11 362 -3.72 0.5056
2016-08-15 2016-06-30 13F MERCK COM 58933Y105 6,523 -21 -0.32 376 8.67 0.5444
2016-05-16 2016-03-31 13F MERCK & CO INC COM 58933Y105 6,544 0 0.00 346 0.00 0.4736
2016-02-16 2015-12-31 13F MERCK & CO INC COM 58933Y105 6,544 0 0.00 346 2.67 0.4747
2015-11-17 2015-09-30 13F MERCK & CO INC COM 58933Y105 6,544 0 0.00 337 -10.13 0.4277
2015-07-31 2015-06-30 13F MERCK Stock 58933Y105 6,544 0 0.00 375 -0.27 0.4366
2015-05-12 2015-03-31 13F MERCK Stock 58933Y105 6,544 0 0.00 376 1.08 0.4437
2015-02-13 2014-12-31 13F MERCK Stock 58933Y105 6,544 0 0.00 372 5.08 0.4290
2014-11-12 2014-09-30 13F MERCK & CO INC NEW COM Stock 58933Y105 6,544 0 0.00 354 -6.84 0.3862
2014-08-14 2014-06-30 13F MERCK & CO INC COM 58933Y105 6,544 0 0.00 380 4.40 0.4525
2014-05-15 2014-03-31 13F MERCK Common Stock 58933Y105 6,544 0 0.00 364 10.98 0.4324
2014-02-18 2013-12-31 13F MERCK & CO INC COM 58933Y105 6,544 466 7.67 328 15.49 0.3520
2013-08-15 2013-06-30 13F MERCK & CO INC COM 58933Y105 6,078 6,078 284 0.2944
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.