Merck & Co., Inc.
DE ˙ XTRA ˙ US58933Y1055
102,78 € ↑2,84 (2,84%)
2026-06-04
DEL PRIS
SecurityDE:6MK / Merck & Co., Inc.
InstitutionFmr Llc
Latest Disclosed Ownership44,516,010 shares
Latest Disclosed Value $ 5,354,830,881
Fmr Llc reports 9.01% increase in ownership of 6MK / Merck & Co., Inc.

On May 15, 2026 - Fmr Llc filed a 13F-HR form disclosing ownership of 44,516,010 shares of Merck & Co., Inc. (DE:6MK) valued at $4,638,568,242 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 40,836,566 shares of Merck & Co., Inc.. This represents a change in shares of 9.01% during the quarter. The current value of the position is $4,575,355,508 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)
2026-05-15 2026-03-31 13F MERCK COM 58933Y105 44,516,010 3,679,444 9.01 5,354,831 24.58 0.0560
2026-02-17 2025-12-31 13F MERCK COM 58933Y105 40,836,566 7,409,816 22.17 4,298,457 53.21 0.2192
2025-11-13 2025-09-30 13F MERCK COM 58933Y105 33,426,750 1,860,625 5.89 2,805,507 12.28 0.1459
2025-08-14 2025-06-30 13F MERCK COM 58933Y105 31,566,125 -241,918 -0.76 2,498,775 -12.48 0.1409
2025-05-12 2025-03-31 13F MERCK COM 58933Y105 31,808,043 -5,552,529 -14.86 2,855,090 -23.18 0.1823
2025-02-13 2024-12-31 13F MERCK COM 58933Y105 37,360,572 -12,345,732 -24.84 3,716,630 -34.16 0.2218
2024-11-13 2024-09-30 13F MERCK COM 58933Y105 49,706,304 -946,950 -1.87 5,644,648 -9.99 0.3435
2024-08-13 2024-06-30 13F MERCK COM 58933Y105 50,653,254 -1,517,665 -2.91 6,270,873 -8.91 0.4014
2024-05-13 2024-03-31 13F MERCK COM 58933Y105 52,170,919 9,370,902 21.89 6,883,953 47.53 0.4622
2024-02-13 2023-12-31 13F MERCK COM 58933Y105 42,800,017 4,654,819 12.20 4,666,058 18.82 0.3584
2023-11-13 2023-09-30 13F MERCK COM 58933Y105 38,145,198 -819,448 -2.10 3,927,048 -12.66 0.3394
2023-08-11 2023-06-30 13F MERCK COM 58933Y105 38,964,646 3,229,721 9.04 4,496,131 18.26 0.3769
2023-08-11 2023-03-31 13F/A-1 MERCK COM 58933Y105 35,734,925 8,281,942 30.17 3,801,839 24.82 0.3478
2023-05-11 2023-03-31 13F MERCK COM 58933Y105 35,734,925 8,281,942 3,801,839 0.0692
2023-02-13 2022-12-31 13F MERCK COM 58933Y105 27,452,983 4,255,943 18.35 3,045,908 52.47 0.3026
2022-11-10 2022-09-30 13F MERCK COM 58933Y105 23,197,040 847,491 3.79 1,997,729 -1.96 0.2083
2022-08-12 2022-06-30 13F MERCK COM 58933Y105 22,349,549 7,816,470 53.78 2,037,608 70.88 0.2030
2022-05-13 2022-03-31 13F MERCK COM 58933Y105 14,533,079 463,078 3.29 1,192,437 10.58 0.0953
2022-02-14 2021-12-31 13F MERCK COM 58933Y105 14,070,001 3,382,119 31.64 1,078,323 34.33 0.0796
2022-02-14 2021-09-30 13F/A-1 MERCK COM 58933Y105 10,687,882 330,009 3.19 802,767 -0.34 0.0637
2021-11-15 2021-09-30 13F MERCK COM 58933Y105 10,687,882 330,009 802,767 0.0637
2021-08-13 2021-06-30 13F MERCK COM 58933Y105 10,357,873 4,165,565 67.27 805,532 68.75 0.0631
2021-05-14 2021-03-31 13F MERCK & CO. COM 58933Y105 6,192,308 -1,427,834 -18.74 477,365 -23.42 0.0408
2021-02-08 2020-12-31 13F MERCK & CO. COM 58933Y105 7,620,142 -4,519,582 -37.23 623,326 -38.10 0.0555
2020-11-13 2020-09-30 13F MERCK & CO. COM 58933Y105 12,139,724 -817,929 -6.31 1,006,990 0.50 0.1018
2020-08-24 2020-06-30 13F/A-1 MERCK & CO. COM 58933Y105 12,957,653 41,706 0.32 1,002,015 0.83 0.1102
2020-08-13 2020-06-30 13F MERCK & CO. COM 58933Y105 12,957,653 41,706 1,002,015 24,616.5763
2020-05-14 2020-03-31 13F MERCK & CO. COM 58933Y105 12,915,947 429,724 3.44 993,754 -12.49 0.1376
2020-02-07 2019-12-31 13F MERCK COM 58933Y105 12,486,223 822,959 7.06 1,135,622 15.67 0.1253
2019-11-13 2019-09-30 13F MERCK COM 58933Y105 11,663,264 678,225 6.17 981,814 6.59 0.1178
2019-08-13 2019-06-30 13F MERCK COM 58933Y105 10,985,039 -126,405 -1.14 921,095 -0.33 0.1076
2019-05-13 2019-03-31 13F MERCK COM 58933Y105 11,111,444 3,244,078 41.23 924,139 53.73 0.1107
2019-02-13 2018-12-31 13F MERCK COM 58933Y105 7,867,366 2,995,599 61.49 601,145 73.94 0.0823
2018-11-09 2018-09-30 13F MERCK COM 58933Y105 4,871,767 -165,495 -3.29 345,603 13.03 0.0389
2018-08-10 2018-06-30 13F MERCK COM 58933Y105 5,037,262 157,592 3.23 305,762 15.04 0.0361
2018-05-14 2018-03-31 13F MERCK COM 58933Y105 4,879,670 -1,107,413 -18.50 265,796 -21.10 0.0316
2018-02-12 2017-12-31 13F MERCK COM 58933Y105 5,987,083 -5,748,751 -48.98 336,893 -55.17 0.0395
2017-11-13 2017-09-30 13F MERCK COM 58933Y105 11,735,834 -1,398,905 -10.65 751,445 -10.73 0.0909
2017-08-29 2017-06-30 13F/A-1 MERCK COM 58933Y105 13,134,739 171,411 1.32 841,805 2.20 0.1046
2017-08-11 2017-06-30 13F MERCK COM 58933Y105 13,134,739 171,411 841,805
2017-05-11 2017-03-31 13F MERCK COM 58933Y105 12,963,328 -525,353 -3.89 823,691 3.73 0.1046
2017-02-10 2016-12-31 13F MERCK COM 58933Y105 13,488,681 -120,675 -0.89 794,078 -6.51 0.1061
2016-11-14 2016-09-30 13F MERCK COM 58933Y105 13,609,356 -8,757 -0.06 849,361 8.26 0.1131
2016-08-11 2016-06-30 13F MERCK COM 58933Y105 13,618,113 699,598 5.42 784,540 14.78 0.1071
2016-05-16 2016-03-31 13F MERCK & CO INC COM 58933Y105 12,918,515 1,430,764 12.45 683,518 12.65 0.0946
2016-02-12 2015-12-31 13F MERCK & CO INC COM 58933Y105 11,487,751 1,368,012 13.52 606,783 21.40 0.0816
2015-11-10 2015-09-30 13F MERCK & CO INC COM 58933Y105 10,119,739 -762,769 -7.01 499,813 -19.33 0.0712
2015-08-25 2015-06-30 13F/A-1 MERCK & CO INC COM 58933Y105 10,882,508 -5,782,701 -34.70 619,542 -35.32 0.0794
2015-08-13 2015-06-30 13F MERCK & CO INC COM 58933Y105 10,882,508 619,542
2015-05-14 2015-03-31 13F MERCK & CO INC COM 58933Y105 16,665,209 -2,456,902 -12.85 957,916 -11.79 0.1220
2015-02-17 2014-12-31 13F MERCK & CO INC COM 58933Y105 19,122,111 -14,759,935 -43.56 1,085,944 -45.93 0.1413
2014-11-14 2014-09-30 13F MERCK & CO INC COM 58933Y105 33,882,046 -14,767,410 -30.35 2,008,528 -28.63 0.2720
2014-08-14 2014-06-30 13F MERCK & CO INC COM 58933Y105 48,649,456 -10,888,783 -18.29 2,814,371 -16.73 0.3772
2014-05-15 2014-03-31 13F MERCK & CO INC COM 58933Y105 59,538,239 6,266,403 11.76 3,379,985 26.77 0.4693
2014-02-13 2013-12-31 13F MERCK & CO INC COM 58933Y105 53,271,836 -8,049,232 -13.13 2,666,257 -8.67 0.3768
2013-11-14 2013-09-30 13F MERCK & CO INC COM 58933Y105 61,321,068 -12,790,245 -17.26 2,919,496 -15.19 0.4474
2013-09-24 2013-06-30 13F/A-1 MERCK & CO INC COM 58933Y105 74,111,313 74,111,313 3,442,471 0.5635
2013-08-14 2013-06-30 13F MERCK & CO INC COM 58933Y105 74,111,313 3,442,471 0.5635
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.