Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionWeatherly Asset Management L. P.
Latest Disclosed Ownership5,954 shares
Latest Disclosed Value $ 720,405
Weatherly Asset Management L. P. reports 0.42% increase in ownership of MRK / Merck & Co., Inc.

On April 15, 2026 - Weatherly Asset Management L. P. filed a 13F-HR form disclosing ownership of 5,954 shares of Merck & Co., Inc. (MX:MRK) valued at $720,405 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 16, 2026 disclosing 5,929 shares of Merck & Co., Inc.. This represents a change in shares of 0.42% 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)
2026-04-15 2026-03-31 13F MERCK COMMON 58933Y105 5,954 25 0.42 720 14.65 0.0583
2026-01-16 2025-12-31 13F MERCK COMMON 58933Y105 5,929 9 0.15 628 25.35 0.0484
2025-10-16 2025-09-30 13F MERCK COMMON 58933Y105 5,920 -275 -4.44 501 1.42 0.0413
2025-07-11 2025-06-30 13F MERCK COMMON 58933Y105 6,195 38 0.62 495 -11.15 0.0421
2025-05-01 2025-03-31 13F MERCK COMMON 58933Y105 6,157 45 0.74 557 -9.15 0.0499
2025-01-29 2024-12-31 13F MERCK COMMON 58933Y105 6,112 -100 -1.61 612 -13.68 0.0543
2024-10-29 2024-09-30 13F MERCK COMMON 58933Y105 6,212 1,143 22.55 710 12.36 0.0622
2024-07-31 2024-06-30 13F MERCK COMMON 58933Y105 5,069 -1,562 -23.56 631 -28.30 0.0578
2024-04-19 2024-03-31 13F MERCK COMMON 58933Y105 6,631 -722 -9.82 880 9.05 0.0851
2024-02-01 2023-12-31 13F MERCK COMMON 58933Y105 7,353 -76 -1.02 807 4.81 0.0870
2023-10-10 2023-09-30 13F MERCK COMMON 58933Y105 7,429 -275 -3.57 770 -13.87 0.0920
2023-07-21 2023-06-30 13F MERCK COMMON 58933Y105 7,704 0 0.00 895 8.36 0.1044
2023-04-13 2023-03-31 13F MERCK COMMON 58933Y105 7,704 -109 -1.40 825 -5.39 0.1071
2023-01-11 2022-12-31 13F MERCK COMMON 58933Y105 7,813 -227 -2.82 873 24.93 0.1191
2022-10-17 2022-09-30 13F MERCK COMMON 58933Y105 8,040 0 0.00 698 -5.55 0.1003
2022-07-18 2022-06-30 13F MERCK COMMON 58933Y105 8,040 -42 -0.52 739 11.46 0.1029
2022-05-06 2022-03-31 13F MERCK COMMON 58933Y105 8,082 102 1.28 663 8.33 0.0776
2022-01-28 2021-12-31 13F MERCK COMMON 58933Y105 7,980 -273 -3.31 612 -1.29 0.0679
2021-11-05 2021-09-30 13F MERCK COMMON 58933Y105 8,253 2,447 42.15 620 37.17 0.0754
2021-08-12 2021-06-30 13F MERCK COMMON 58933Y105 5,806 0 0.00 452 0.89 0.0570
2021-05-05 2021-03-31 13F MERCK & CO. COMMON 58933Y105 5,806 -45 -0.77 448 -6.47 0.0622
2021-02-02 2020-12-31 13F MERCK & CO. COMMON 58933Y105 5,851 22 0.38 479 -1.03 0.0688
2020-10-30 2020-09-30 13F MERCK & CO. COMMON 58933Y105 5,829 -66 -1.12 484 6.14 0.0781
2020-07-29 2020-06-30 13F MERCK & CO. COMMON 58933Y105 5,895 0 0.00 456 0.44 0.0806
2020-05-01 2020-03-31 13F MERCK & CO. COMMON 58933Y105 5,895 -116 -1.93 454 -17.00 0.0993
2020-01-23 2019-12-31 13F MERCK COMMON 58933Y105 6,011 -567 -8.62 547 -1.26 0.1045
2019-11-07 2019-09-30 13F MERCK COMMON 58933Y105 6,578 -1,126 -14.62 554 -14.24 0.1180
2019-07-31 2019-06-30 13F MERCK COMMON 58933Y105 7,704 -169 -2.15 646 -1.37 0.1287
2019-05-01 2019-03-31 13F MERCK COMMON 58933Y105 7,873 67 0.86 655 9.90 0.1338
2019-02-11 2018-12-31 13F MERCK COMMON 58933Y105 7,806 440 5.97 596 13.96 0.1411
2018-11-08 2018-09-30 13F MERCK COMMON 58933Y105 7,366 110 1.52 523 18.86 0.1073
2018-07-31 2018-06-30 13F MERCK COMMON 58933Y105 7,256 0 0.00 440 11.39 0.1027
2018-05-07 2018-03-31 13F MERCK COMMON 58933Y105 7,256 0 0.00 395 -3.19 0.0936
2018-01-30 2017-12-31 13F MERCK COMMON 58933Y105 7,256 -32 -0.44 408 -12.63 0.0986
2017-10-20 2017-09-30 13F MERCK COMMON 58933Y105 7,288 -138 -1.86 467 -1.89 0.1239
2017-07-27 2017-06-30 13F MERCK COMMON 58933Y105 7,426 42 0.57 476 1.49 0.1340
2017-04-28 2017-03-31 13F MERCK COMMON 58933Y105 7,384 -129 -1.72 469 6.11 0.1385
2017-02-14 2016-12-31 13F MERCK COMMON 58933Y105 7,513 -2,193 -22.59 442 -27.06 0.1407
2016-10-31 2016-09-30 13F MERCK COMMON 58933Y105 9,706 -1,600 -14.15 606 -6.91 0.2010
2016-08-06 2016-06-30 13F/A-1 MERCK COMMON 58933Y105 11,306 -120 -1.05 651 7.78 0.2148
2016-08-05 2016-06-30 13F MERCK COMMON 58933Y105 11,866 440 636 0.2709
2016-04-21 2016-03-31 13F MERCK & CO INC COMMON 58933Y105 11,426 87 0.77 604 1.00 0.2088
2016-02-09 2015-12-31 13F MERCK & CO INC COMMON 58933Y105 11,339 1,675 17.33 598 25.37 0.2116
2015-11-05 2015-09-30 13F/A-1 MERCK COMMON 58933Y105 9,664 0 0.00 477 -13.27 0.1928
2015-10-15 2015-09-30 13F MERCK COMMON 58933Y105 9,664 0 477 0.1932
2015-07-30 2015-06-30 13F MERCK COMMON 58933Y105 9,664 -461 -4.55 550 -5.34 0.2095
2015-04-30 2015-03-31 13F MERCK COMMON 58933Y105 10,125 10,125 0.00 581 0.2322
2015-02-05 2014-12-31 13F MERCK COMMON 58933Y105 0 -9,987 -100.00 0 -100.00
2014-10-03 2014-09-30 13F MERCK COMMON 58933Y105 9,987 -260 -2.54 592 -0.17 0.2549
2014-07-03 2014-06-30 13F/A-1 MERCK COMMON 58933Y105 10,247 -125 -1.21 593 0.68 0.2484
2014-07-03 2014-06-30 13F MERCK COMMON 58933Y105 10,247 -125 593 0.2585
2014-04-17 2014-03-31 13F MERCK COMMON 58933Y105 10,372 49 0.47 589 13.93 0.2733
2014-01-13 2013-12-31 13F MERCK COMMON 58933Y105 10,323 125 1.23 517 6.38 0.2466
2013-11-12 2013-09-30 13F MERCK COM 58933Y105 10,198 315 3.19 486 5.88 0.2471
2013-08-01 2013-06-30 13F MERCK COM 58933Y105 9,883 9,883 459 0.2531
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.