Merck & Co., Inc.
DE ˙ XTRA ˙ US58933Y1055
102,78 € ↑2,84 (2,84%)
2026-06-04
DEL PRIS
SecurityDE:6MK / Merck & Co., Inc.
InstitutionBanco Santander, S.A.
Latest Disclosed Ownership115,528 shares
Latest Disclosed Value $ 13,896,864
Banco Santander, S.A. reports 1.23% increase in ownership of 6MK / Merck & Co., Inc.

On May 8, 2026 - Banco Santander, S.A. filed a 13F-HR form disclosing ownership of 115,528 shares of Merck & Co., Inc. (DE:6MK) valued at $12,038,018 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 114,124 shares of Merck & Co., Inc.. This represents a change in shares of 1.23% during the quarter. The current value of the position is $11,873,968 USD.

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)
2026-05-08 2026-03-31 13F MERCK COM 58933Y105 115,528 1,404 1.23 13,897 15.68 0.1121
2026-02-13 2025-12-31 13F MERCK COM 58933Y105 114,124 -40,944 -26.40 12,013 -7.70 0.0900
2025-11-12 2025-09-30 13F MERCK COM 58933Y105 155,068 -216,463 -58.26 13,015 -55.75 0.1156
2025-08-01 2025-06-30 13F MERCK COM 58933Y105 371,531 54,618 17.23 29,410 3.39 0.2793
2025-05-09 2025-03-31 13F MERCK COM 58933Y105 316,913 -190,114 -37.50 28,446 -43.60 0.3139
2025-02-07 2024-12-31 13F MERCK COM 58933Y105 507,027 11,470 2.31 50,439 -10.37 0.6068
2024-11-12 2024-09-30 13F MERCK COM 58933Y105 495,557 -4,817 -0.96 56,275 -9.15 0.6633
2024-07-29 2024-06-30 13F MERCK COM 58933Y105 500,374 36,176 7.79 61,946 1.14 0.7677
2024-05-10 2024-03-31 13F MERCK COM 58933Y105 464,198 134,522 40.80 61,251 70.42 0.7384
2024-02-09 2023-12-31 13F MERCK COM 58933Y105 329,676 31,014 10.38 35,941 16.89 0.4247
2023-11-08 2023-09-30 13F MERCK COM 58933Y105 298,662 -1,758 -0.59 30,747 -11.30 0.4359
2023-08-14 2023-06-30 13F MERCK COM 58933Y105 300,420 9,809 3.38 34,665 12.12 0.4547
2023-05-10 2023-03-31 13F MERCK COM 58933Y105 290,611 6,051 2.13 30,918 -2.07 0.4627
2023-02-13 2022-12-31 13F MERCK COM 58933Y105 284,560 -270,646 -48.75 31,572 -33.97 0.4741
2022-11-08 2022-09-30 13F MERCK COM 58933Y105 555,206 19,420 3.62 47,814 -2.12 0.6379
2022-07-28 2022-06-30 13F MERCK COM 58933Y105 535,786 11,097 2.11 48,848 13.47 0.6510
2022-05-09 2022-03-31 13F MERCK COM 58933Y105 524,689 -28,319 -5.12 43,050 1.57 0.4621
2022-02-09 2021-12-31 13F MERCK COM 58933Y105 553,008 38,259 7.43 42,383 9.62 0.2284
2021-11-08 2021-09-30 13F MERCK COM 58933Y105 514,749 47,879 10.26 38,663 6.49 0.2077
2021-07-29 2021-06-30 13F MERCK COM 58933Y105 466,870 156,573 50.46 36,308 51.78 0.2028
2021-05-10 2021-03-31 13F MERCK & CO. COM 58933Y105 310,297 4,996 1.64 23,921 -4.22 0.1686
2021-02-12 2020-12-31 13F MERCK & CO. COM 58933Y105 305,301 25,130 8.97 24,974 7.46 0.1790
2020-11-09 2020-09-30 13F MERCK & CO. COM 58933Y105 280,171 7,137 2.61 23,241 10.07 0.3056
2020-08-05 2020-06-30 13F MERCK & CO. COM 58933Y105 273,034 1,417 0.52 21,114 1.03 0.2739
2020-05-11 2020-03-31 13F MERCK & CO. COM 58933Y105 271,617 27,758 11.38 20,899 -5.77 0.2393
2020-02-07 2019-12-31 13F MERCK COM 58933Y105 243,859 1,621 0.67 22,179 8.77 0.2049
2019-11-06 2019-09-30 13F MERCK COM 58933Y105 242,238 -74,230 -23.46 20,391 -23.16 0.1983
2019-08-07 2019-06-30 13F MERCK COM 58933Y105 316,468 23,830 8.14 26,536 9.03 0.2693
2019-05-13 2019-03-31 13F MERCK COM 58933Y105 292,638 -47,408 -13.94 24,339 -6.32 0.2748
2019-02-12 2018-12-31 13F MERCK COM 58933Y105 340,046 10,666 3.24 25,982 11.20 0.3283
2018-11-13 2018-09-30 13F MERCK COM 58933Y105 329,380 -34,991 -9.60 23,366 5.64 0.2666
2018-08-14 2018-06-30 13F MERCK COM 58933Y105 364,371 -42,458 -10.44 22,118 -0.19 0.2577
2018-05-14 2018-03-31 13F MERCK COM 58933Y105 406,829 265,757 188.38 22,159 179.12 0.2592
2018-02-14 2017-12-31 13F MERCK COM 58933Y105 141,072 6,959 5.19 7,939 -7.43 0.1137
2017-11-13 2017-09-30 13F MERCK COM 58933Y105 134,113 -2,693 -1.97 8,576 -2.30 0.1414
2017-08-11 2017-06-30 13F MERCK COM 58933Y105 136,806 -112,397 -45.10 8,778 -44.56 0.1723
2017-05-12 2017-03-31 13F MERCK COM 58933Y105 249,203 58,246 30.50 15,834 47.18 0.4084
2017-02-17 2016-12-31 13F/A-1 MERCK COM 58933Y105 190,957 190,957 10,758 0.2835
2017-02-14 2016-12-31 13F MERCK COM 58933Y105 190,957 10,758
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.