Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionWaters Parkerson & Co., Llc
Latest Disclosed Ownership351,577 shares
Latest Disclosed Value $ 42,291,165
Waters Parkerson & Co., Llc reports 0.04% decrease in ownership of MRK / Merck & Co., Inc.

On April 29, 2026 - Waters Parkerson & Co., Llc filed a 13F-HR form disclosing ownership of 351,577 shares of Merck & Co., Inc. (MX:MRK) valued at $42,291,165 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 12, 2026 disclosing 351,723 shares of Merck & Co., Inc.. This represents a change in shares of -0.04% 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)
2026-04-29 2026-03-31 13F MERCK COM 58933Y105 351,577 -146 -0.04 42,291 14.23 2.1742
2026-02-12 2025-12-31 13F MERCK COM 58933Y105 351,723 10,810 3.17 37,022 29.39 1.8189
2025-10-28 2025-09-30 13F MERCK COM 58933Y105 340,913 7,831 2.35 28,613 8.52 1.3948
2025-08-14 2025-06-30 13F MERCK COM 58933Y105 333,082 12,665 3.95 26,367 -8.32 1.3153
2025-05-15 2025-03-31 13F MERCK COM 58933Y105 320,417 12,395 4.02 28,761 -6.14 1.5345
2025-02-14 2024-12-31 13F MERCK COM 58933Y105 308,022 5,743 1.90 30,642 90,023.53 1.6146
2024-11-13 2024-09-30 13F MERCK & CO INC COM Com 58933Y105 302,279 -4,453 -1.45 34 -8.11 1.7413
2024-08-13 2024-06-30 13F MERCK & CO INC COM Com 58933Y105 306,732 -1,543 -0.50 38 -7.50 2.0211
2024-05-14 2024-03-31 13F MERCK & CO INC COM Com 58933Y105 308,275 -12,883 -4.01 41 14.29 2.0888
2024-02-14 2023-12-31 13F MERCK & CO INC COM Com 58933Y105 321,158 -9,922 -3.00 35 2.94 1.9390
2023-11-09 2023-09-30 13F MERCK & CO INC COM Com 58933Y105 331,080 -1,823 -0.55 34 -10.53 2.0396
2023-08-14 2023-06-30 13F MERCK & CO INC COM Com 58933Y105 332,903 -5,122 -1.52 38 8.57 2.1714
2023-05-02 2023-03-31 13F MERCK & CO INC COM Com 58933Y105 338,025 -542 -0.16 36 -5.41 2.1238
2023-02-10 2022-12-31 13F MERCK & CO INC COM Com 58933Y105 338,567 -6,894 -2.00 38 -99.88 2.2598
2022-11-07 2022-09-30 13F MERCK & CO INC COM Com 58933Y105 345,461 -1,582 -0.46 29,751 -5.97 1.9928
2022-08-01 2022-06-30 13F MERCK & CO INC COM Com 58933Y105 347,043 4,034 1.18 31,640 12.42 1.9980
2022-05-13 2022-03-31 13F MERCK & CO. INC COM Com 58933Y105 343,009 4,035 1.19 28,144 8.33 1.5697
2022-02-14 2021-12-31 13F MERCK & CO. INC COM Com 58933Y105 338,974 -10,687 -3.06 25,979 -1.08 1.3719
2021-11-04 2021-09-30 13F MERCK & CO. INC COM Com 58933Y105 349,661 4,993 1.45 26,263 -2.02 1.5123
2021-08-10 2021-06-30 13F MERCK & CO. INC COM Com 58933Y105 344,668 8,298 2.47 26,805 3.37 1.5495
2021-05-12 2021-03-31 13F MERCK & CO. INC COM Com 58933Y105 336,370 16,069 5.02 25,931 -1.03 1.6002
2021-02-10 2020-12-31 13F MERCK & CO. INC COM Com 58933Y105 320,301 4,292 1.36 26,201 -0.05 1.7503
2020-11-16 2020-09-30 13F MERCK & CO. INC COM Com 58933Y105 316,009 -1,680 -0.53 26,213 6.70 1.9695
2020-08-13 2020-06-30 13F MERCK & CO INC COM Com 58933Y105 317,689 458 0.14 24,567 0.65 1.9930
2020-05-11 2020-03-31 13F MERCK & CO INC COM Com 58933Y105 317,231 10,907 3.56 24,408 -12.39 2.3704
2020-02-13 2019-12-31 13F MERCK & CO INC COM Com 58933Y105 306,324 -1,285 -0.42 27,860 7.59 2.0867
2019-11-13 2019-09-30 13F MERCK & CO INC COM Com 58933Y105 307,609 -5,449 -1.74 25,895 -1.35 2.0875
2019-08-06 2019-06-30 13F MERCK & CO INC COM Com 58933Y105 313,058 -6,330 -1.98 26,250 -1.18 2.1272
2019-05-13 2019-03-31 13F MERCK & CO INC COM Com 58933Y105 319,388 1,956 0.62 26,564 9.52 2.2316
2019-02-12 2018-12-31 13F MERCK & CO INC COM Com 58933Y105 317,432 -1,670 -0.52 24,255 7.15 2.3405
2018-11-13 2018-09-30 13F MERCK & CO INC COM Com 58933Y105 319,102 943 0.30 22,637 17.22 1.8481
2018-08-13 2018-06-30 13F MERCK & CO INC COM Com 58933Y105 318,159 2,943 0.93 19,312 12.48 1.6601
2018-05-08 2018-03-31 13F MERCK Com 58933Y105 315,216 17,096 5.73 17,170 2.35 1.5060
2018-02-09 2017-12-31 13F MERCK Com 58933Y105 298,120 20,673 7.45 16,775 -5.57 1.4116
2017-11-13 2017-09-30 13F MERCK Com 58933Y105 277,447 593 0.21 17,765 0.12 1.5674
2017-08-11 2017-06-30 13F MERCK & CO INC NEW COM Com 58933Y105 276,854 1,872 0.68 17,744 1.56 1.6417
2017-05-12 2017-03-31 13F MERCK & CO INC NEW COM Com 58933Y105 274,982 -1,465 -0.53 17,472 7.36 1.6532
2017-02-15 2016-12-31 13F MERCK & CO INC NEW COM Com 58933Y105 276,447 -9,713 -3.39 16,274 -8.88 1.6405
2016-11-14 2016-09-30 13F MERCK & CO INC NEW COM Com 58933Y105 286,160 -3,569 -1.23 17,859 7.00 1.8288
2016-08-10 2016-06-30 13F MERCK & CO INC NEW COM Com 58933Y105 289,729 4,418 1.55 16,691 10.57 1.7879
2016-05-16 2016-03-31 13F MERCK & CO INC NEW COM Com 58933Y105 285,311 10,629 3.87 15,096 4.05 1.6674
2016-02-16 2015-12-31 13F MERCK & CO INC NEW COM Com 58933Y105 274,682 8,809 3.31 14,509 10.49 1.6626
2015-11-16 2015-09-30 13F MERCK & CO INC NEW COM Com 58933Y105 265,873 7,412 2.87 13,131 -10.76 1.6718
2015-08-13 2015-06-30 13F MERCK & CO INC NEW COM Com 58933Y105 258,461 4,426 1.74 14,714 0.77 1.7257
2015-05-11 2015-03-31 13F MERCK & CO INC NEW COM Com 58933Y105 254,035 4,518 1.81 14,602 3.05 1.7104
2015-02-13 2014-12-31 13F MERCK & CO INC NEW COM Com 58933Y105 249,517 5,458 2.24 14,170 -2.06 1.6792
2014-11-13 2014-09-30 13F MERCK & CO INC NEW COM Com 58933Y105 244,059 1,122 0.46 14,468 2.95 1.7344
2014-08-12 2014-06-30 13F MERCK & CO INC NEW COM Com 58933Y105 242,937 -487 -0.20 14,054 1.70 1.6816
2014-05-08 2014-03-31 13F MERCK & CO INC NEW COM Com 58933Y105 243,424 -4,486 -1.81 13,819 11.37 1.7076
2014-02-07 2013-12-31 13F MERCK & CO INC NEW COM Com 58933Y105 247,910 6,096 2.52 12,408 7.77 1.5208
2013-11-15 2013-09-30 13F MERCK & CO INC NEW COM Com 58933Y105 241,814 -1,195 -0.49 11,513 1.99 1.5497
2013-11-18 2013-06-30 13F MERCK & CO INC NEW COM Com 58933Y105 243,009 243,009 11,288 1.6415
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.