Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionLegal & General Group Plc
Latest Disclosed Ownership19,538,545 shares
Latest Disclosed Value $ 2,350,291,572
Legal & General Group Plc reports 1.20% decrease in ownership of MRK / Merck & Co., Inc.

On May 8, 2026 - Legal & General Group Plc filed a 13F-HR form disclosing ownership of 19,538,545 shares of Merck & Co., Inc. (MX:MRK) valued at $2,350,291,572 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 9, 2026 disclosing 19,776,842 shares of Merck & Co., Inc.. This represents a change in shares of -1.20% 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)
2026-05-08 2026-03-31 13F MERCK COM 58933Y105 19,538,545 -238,297 -1.20 2,350,292 12.90 0.5436
2026-02-09 2025-12-31 13F MERCK COM 58933Y105 19,776,842 -882,315 -4.27 2,081,710 20.06 0.4617
2025-11-13 2025-09-30 13F MERCK COM 58933Y105 20,659,157 1,156,112 5.93 1,733,923 12.31 0.3890
2025-08-12 2025-06-30 13F MERCK COM 58933Y105 19,503,045 -252,263 -1.28 1,543,861 -12.94 0.3832
2025-05-15 2025-03-31 13F MERCK COM 58933Y105 19,755,308 270,797 1.39 1,773,236 -8.52 0.4829
2025-02-13 2024-12-31 13F MERCK COM 58933Y105 19,484,511 241,709 1.26 1,938,319 -11.30 0.5129
2025-02-28 2024-09-30 13F/A-2 MERCK COM 58933Y105 19,242,802 555,695 2.97 2,185,213 -5.54 0.5749
2024-11-14 2024-09-30 13F/A-1 MERCK COM 58933Y105 23,554,443 128,276 2,674,843 0.5574
2024-11-14 2024-09-30 13F MERCK COM 58933Y105 23,554,443 128,276 2,674,843 0.2814
2025-05-29 2024-06-30 13F/A-1 MERCK COM 58933Y105 18,687,107 -555,928 -2.89 2,313,466 -8.89 0.6536
2024-08-14 2024-06-30 13F MERCK COM 58933Y105 23,426,167 50,035 2,900,162 0.6492
2025-05-29 2024-03-31 13F/A-2 MERCK COM 58933Y105 19,243,035 -144,648 -0.75 2,539,115 20.13 0.7311
2024-07-01 2024-03-31 13F/A-1 MERCK COM 58933Y105 23,376,132 -115,534 3,084,477 0.7201
2024-05-14 2024-03-31 13F MERCK COM 58933Y105 23,376,132 -115,534 3,084,477 0.3709
2025-05-29 2023-12-31 13F/A-1 MERCK COM 58933Y105 19,387,683 -752,004 -3.73 2,113,646 1.94 0.6567
2024-02-15 2023-12-31 13F MERCK COM 58933Y105 23,491,666 3,351,979 2,561,062 0.6572
2023-11-14 2023-09-30 13F MERCK COM 58933Y105 20,139,687 -545,917 -2.64 2,073,385 -13.14 0.7234
2023-08-14 2023-06-30 13F MERCK COM 58933Y105 20,685,604 1,097,735 5.60 2,386,907 14.54 0.7765
2023-05-15 2023-03-31 13F MERCK COM 58933Y105 19,587,869 398,252 2.08 2,083,951 -2.12 0.7454
2023-02-14 2022-12-31 13F MERCK COM 58933Y105 19,189,617 -514,995 -2.61 2,129,088 25.46 0.8172
2022-11-14 2022-09-30 13F MERCK COM 58933Y105 19,704,612 -575,045 -2.84 1,696,967 -8.22 0.6630
2022-08-22 2022-06-30 13F MERCK COM 58933Y105 20,279,657 -17,399 -0.09 1,848,915 11.02 0.6543
2022-05-16 2022-03-31 13F MERCK COM 58933Y105 20,297,056 1,192,643 6.24 1,665,374 13.74 0.5066
2022-02-14 2021-12-31 13F MERCK COM 58933Y105 19,104,413 -12,213 -0.06 1,464,163 1.97 0.4428
2021-11-15 2021-09-30 13F MERCK COM 58933Y105 19,116,626 832,409 4.55 1,435,849 0.98 0.4668
2021-08-12 2021-06-30 13F MERCK COM 58933Y105 18,284,217 1,269,432 7.46 1,421,965 8.41 0.4754
2021-05-17 2021-03-31 13F MERCK & CO. COM 58933Y105 17,014,785 -260,298 -1.51 1,311,670 -7.18 0.4886
2021-02-12 2020-12-31 13F MERCK & CO. COM 58933Y105 17,275,083 249,739 1.47 1,413,099 0.06 0.5534
2020-11-13 2020-09-30 13F MERCK & CO. COM 58933Y105 17,025,344 -221,817 -1.29 1,412,239 5.89 0.6311
2020-08-14 2020-06-30 13F MERCK & CO. COM 58933Y105 17,247,161 316,699 1.87 1,333,646 2.31 0.6445
2020-05-14 2020-03-31 13F MERCK & CO. COM 58933Y105 16,930,462 504,582 3.07 1,303,546 -12.74 0.7623
2020-02-13 2019-12-31 13F MERCK COM 58933Y105 16,425,880 685,803 4.36 1,493,939 13.19 0.7117
2019-08-14 2019-06-30 13F MERCK COM 58933Y105 15,740,077 -173,642 -1.09 1,319,812 -0.28 0.7099
2019-05-15 2019-03-31 13F MERCK COM 58933Y105 15,913,719 2,482,234 18.48 1,323,530 28.97 0.7557
2019-02-15 2018-12-31 13F MERCK COM 58933Y105 13,431,485 653,128 5.11 1,026,209 13.21 0.7951
2018-11-20 2018-09-30 13F MERCK COM 58933Y105 12,778,357 -3,986 -0.03 906,499 16.83 0.6489
2018-08-10 2018-06-30 13F MERCK COM 58933Y105 12,782,343 -698,229 -5.18 775,911 5.66 0.5986
2018-05-17 2018-03-31 13F MERCK COM 58933Y105 13,480,572 -850,774 -5.94 734,320 -8.95 0.5603
2018-02-13 2017-12-31 13F MERCK COM 58933Y105 14,331,346 -328,785 -2.24 806,461 -14.08 0.5836
2017-11-09 2017-09-30 13F MERCK COM 58933Y105 14,660,131 95,743 0.66 938,669 0.56 0.7060
2017-08-03 2017-06-30 13F MERCK COM 58933Y105 14,564,388 192,348 1.34 933,445 2.22 0.7541
2017-05-12 2017-03-31 13F MERCK COM 58933Y105 14,372,040 499,364 3.60 913,184 11.81 0.7749
2017-02-13 2016-12-31 13F MERCK COM 58933Y105 13,872,676 71,538 0.52 816,707 -5.18 0.7618
2016-10-12 2016-09-30 13F MERCK COM 58933Y105 13,801,138 56,143 0.41 861,321 8.78 0.8726
2016-08-16 2016-06-30 13F MERCK COM 58933Y105 13,744,995 118,481 0.87 791,771 9.82 0.8343
2016-05-16 2016-03-31 13F MERCK & CO INC COM 58933Y105 13,626,514 152,049 1.13 720,986 1.29 0.7983
2016-02-16 2015-12-31 13F MERCK & CO INC COM 58933Y105 13,474,465 64,886 0.48 711,769 7.47 0.8043
2015-11-13 2015-09-30 13F MERCK & CO INC COM 58933Y105 13,409,579 395,601 3.04 662,286 -10.61 0.8074
2015-07-31 2015-06-30 13F MERCK & CO INC COM 58933Y105 13,013,978 248,447 1.95 740,927 0.96 0.8703
2015-05-14 2015-03-31 13F MERCK & CO INC COM 58933Y105 12,765,531 68,394 0.54 733,849 1.76 0.8772
2015-02-20 2014-12-31 13F/A-1 MERCK & CO INC COM 58933Y105 12,697,137 -342,359 -2.63 721,190 -6.70 0.8484
2015-02-17 2014-12-31 13F MERCK & CO INC COM 58933Y105 12,697,137 -342,359 721,190 0.8884
2014-11-14 2014-09-30 13F MERCK & CO INC COM 58933Y105 13,039,496 -844,520 -6.08 772,993 -3.75 0.9270
2014-08-13 2014-06-30 13F MERCK & CO INC COM 58933Y105 13,884,016 200,919 1.47 803,107 3.42 0.9358
2014-05-14 2014-03-31 13F MERCK & CO INC COM 58933Y105 13,683,097 -277,494 -1.99 776,529 11.14 0.9429
2014-02-07 2013-12-31 13F MERCK & CO INC COM 58933Y105 13,960,591 -42,876 -0.31 698,684 4.79 0.8455
2013-11-12 2013-09-30 13F MERCK & CO INC COM 58933Y105 14,003,467 -500,698 -3.45 666,774 -1.08 0.8783
2013-08-01 2013-06-30 13F MERCK & CO INC COM 58933Y105 14,504,165 14,504,165 674,043 0.9309
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.