Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionWindsor Capital Management, LLC
Latest Disclosed Ownership15,582 shares
Latest Disclosed Value $ 1,874,358
Windsor Capital Management, LLC reports 0.33% increase in ownership of MRK / Merck & Co., Inc.

On April 10, 2026 - Windsor Capital Management, LLC filed a 13F-HR form disclosing ownership of 15,582 shares of Merck & Co., Inc. (MX:MRK) valued at $1,874,358 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 15, 2026 disclosing 15,530 shares of Merck & Co., Inc.. This represents a change in shares of 0.33% 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)
2026-04-10 2026-03-31 13F MERCK COM 58933Y105 15,582 52 0.33 1,874 14.69 0.5282
2026-01-15 2025-12-31 13F MERCK COM 58933Y105 15,530 29 0.19 1,635 25.60 0.4512
2025-10-06 2025-09-30 13F MERCK COM 58933Y105 15,501 -646 -4.00 1,301 1.80 0.3592
2025-07-11 2025-06-30 13F MERCK COM 58933Y105 16,147 -519 -3.11 1,278 -14.52 0.3727
2025-05-02 2025-03-31 13F MERCK COM 58933Y105 16,666 -216 -1.28 1,496 -10.96 0.4591
2025-01-28 2024-12-31 13F MERCK COM 58933Y105 16,882 -688 -3.92 1,680 -15.84 0.4983
2024-10-23 2024-09-30 13F MERCK COM 58933Y105 17,570 -484 -2.68 1,995 -10.74 0.5790
2024-07-26 2024-06-30 13F MERCK COM 58933Y105 18,054 -56 -0.31 2,235 -6.45 0.6916
2024-04-15 2024-03-31 13F MERCK COM 58933Y105 18,110 -237 -1.29 2,390 19.45 0.7410
2024-01-09 2023-12-31 13F MERCK COM 58933Y105 18,347 -161 -0.87 2,000 4.99 0.6542
2023-10-04 2023-09-30 13F MERCK COM 58933Y105 18,508 302 1.66 1,905 -9.29 0.6594
2023-07-13 2023-06-30 13F MERCK COM 58933Y105 18,206 -241 -1.31 2,101 7.03 0.6951
2023-04-10 2023-03-31 13F MERCK COM 58933Y105 18,447 -429 -2.27 1,963 -6.30 0.6751
2023-01-13 2022-12-31 13F MERCK COM 58933Y105 18,876 -574 -2.95 2,094 25.01 0.7625
2022-11-03 2022-09-30 13F MERCK COM 58933Y105 19,450 -207 -1.05 1,675 -6.53 0.6262
2022-07-14 2022-06-30 13F MERCK COM 58933Y105 19,657 -16 -0.08 1,792 11.03 0.6386
2022-05-04 2022-03-31 13F MERCK COM 58933Y105 19,673 438 2.28 1,614 9.50 0.5022
2022-02-07 2021-12-31 13F MERCK COM 58933Y105 19,235 413 2.19 1,474 4.32 0.4446
2021-11-12 2021-09-30 13F MERCK COM 58933Y105 18,822 -124 -0.65 1,413 -4.07 0.4530
2021-08-12 2021-06-30 13F MERCK COM 58933Y105 18,946 -84 -0.44 1,473 0.41 0.4868
2021-05-14 2021-03-31 13F MERCK COM 58933Y105 19,030 -199 -1.03 1,467 -6.68 0.5082
2021-02-08 2020-12-31 13F MERCK COM 58933Y105 19,229 745 4.03 1,572 2.54 0.5870
2020-10-09 2020-09-30 13F MERCK COM 58933Y105 18,484 -129 -0.69 1,533 6.53 0.6405
2020-07-16 2020-06-30 13F MERCK COM 58933Y105 18,613 6,019 47.79 1,439 48.50 0.6201
2020-04-22 2020-03-31 13F MERCK COM 58933Y105 12,594 -74 -0.58 969 -15.89 0.4905
2020-02-12 2019-12-31 13F MERCK COM 58933Y105 12,668 463 3.79 1,152 12.17 0.4847
2019-11-08 2019-09-30 13F MERCK COM 58933Y105 12,205 332 2.80 1,027 3.22 0.4585
2019-08-02 2019-06-30 13F MERCK COM 58933Y105 11,873 182 1.56 995 2.37 0.4574
2019-05-02 2019-03-31 13F MERCK COM 58933Y105 11,691 -312 -2.60 972 6.00 0.4589
2019-02-05 2018-12-31 13F MERCK COM 58933Y105 12,003 520 4.53 917 12.65 0.4744
2018-11-09 2018-09-30 13F MERCK COM 58933Y105 11,483 40 0.35 814 17.29 0.3675
2018-08-02 2018-06-30 13F MERCK COM 58933Y105 11,443 -380 -3.21 694 7.76 0.3234
2018-05-01 2018-03-31 13F MERCK COM 58933Y105 11,823 2,928 32.92 644 28.80 0.3037
2018-01-24 2017-12-31 13F MERCK & CO INC COM COM 58933Y105 8,895 557 6.68 500 -6.37 0.2330
2017-10-17 2017-09-30 13F MERCK & CO INC COM COM 58933Y105 8,338 0 0.00 534 0.00 0.2699
2017-08-08 2017-06-30 13F MERCK & CO INC COM COM 58933Y105 8,338 324 4.04 534 4.91 0.2684
2017-05-09 2017-03-31 13F MERCK & CO INC COM COM 58933Y105 8,014 -702 -8.05 509 -0.78 0.2636
2017-02-10 2016-12-31 13F MERCK & CO INC COM COM 58933Y105 8,716 367 4.40 513 -1.54 0.2769
2016-11-09 2016-09-30 13F MERCK & CO INC COM COM 58933Y105 8,349 359 4.49 521 13.26 0.2851
2016-08-09 2016-06-30 13F MERCK & CO INC NEW COM COM 58933Y105 7,990 642 8.74 460 18.56 0.2686
2016-05-11 2016-03-31 13F MERCK & CO INC NEW COM COM 58933Y105 7,348 248 3.49 388 3.47 0.2411
2016-02-01 2015-12-31 13F MERCK & CO INC NEW COM COM 58933Y105 7,100 -94 -1.31 375 5.63 0.2336
2015-10-15 2015-09-30 13F MERCK COM 58933Y105 7,194 -475 -6.19 355 -18.58 0.2091
2015-07-14 2015-06-30 13F MERCK COM 58933Y105 7,669 1,076 16.32 436 15.04 0.2533
2015-04-09 2015-03-31 13F MERCK COM 58933Y105 6,593 1,241 23.19 379 24.67 0.2190
2015-01-08 2014-12-31 13F MERCK COM 58933Y105 5,352 44 0.83 304 -3.49 0.1710
2014-10-17 2014-09-30 13F MERCK & CO INC NEW COM COM 58933Y105 5,308 -1,974 -27.11 315 -25.18 0.1789
2014-07-08 2014-06-30 13F MERCK COM 58933Y105 7,282 434 6.34 421 8.23 0.2359
2014-04-30 2014-03-31 13F/A-1 MERCK COM 58933Y105 6,848 427 6.65 389 21.18 0.2314
2014-04-28 2014-03-31 13F MERCK COM 58933Y105 6,848 388,798
2014-01-10 2013-12-31 13F MERCK COM 58933Y105 6,421 1,336 26.27 321 32.64 0.1883
2013-10-16 2013-09-30 13F MERCK & CO INC. COM COM 58933Y105 5,085 539 11.86 242 14.69 0.1401
2013-07-17 2013-06-30 13F MERCK & CO INC. COM COM 58933Y105 4,546 4,546 211 0.1266
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.