Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionStandard Life Aberdeen plc
Latest Disclosed Ownership4,665,193 shares
Latest Disclosed Value $ 561,176,067
Standard Life Aberdeen plc reports 0.31% increase in ownership of MRK / Merck & Co., Inc.

On April 29, 2026 - Standard Life Aberdeen plc filed a 13F-HR form disclosing ownership of 4,665,193 shares of Merck & Co., Inc. (MX:MRK) valued at $561,176,067 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 16, 2026 disclosing 4,651,002 shares of Merck & Co., Inc.. This represents a change in shares of 0.31% 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 4,665,193 14,191 0.31 561,176 14.63 0.4917
2026-01-16 2025-12-31 13F MERCK COM 58933Y105 4,651,002 171,379 3.83 489,564 34.86 0.7579
2025-11-07 2025-09-30 13F MERCK COM 58933Y105 4,479,623 -46,708 -1.03 363,029 1.92 0.5742
2025-07-24 2025-06-30 13F MERCK COM 58933Y105 4,526,331 12,338 0.27 356,177 -11.64 0.6059
2025-05-13 2025-03-31 13F MERCK COM 58933Y105 4,513,993 264,668 6.23 403,077 -4.07 0.7860
2025-01-24 2024-12-31 13F MERCK COM 58933Y105 4,249,325 -359,459 -7.80 420,195 -19.54 0.7888
2024-10-25 2024-09-30 13F MERCK COM 58933Y105 4,608,784 -130,256 -2.75 522,221 -10.99 0.9575
2024-08-09 2024-06-30 13F MERCK COM 58933Y105 4,739,040 -141,206 -2.89 586,693 -8.89 1.1246
2024-05-09 2024-03-31 13F MERCK COM 58933Y105 4,880,246 14,717 0.30 643,948 21.40 1.2626
2024-01-31 2023-12-31 13F MERCK COM 58933Y105 4,865,529 -147,306 -2.94 530,440 2.78 1.1500
2023-11-07 2023-09-30 13F MERCK COM 58933Y105 5,012,835 -770,083 -13.32 516,071 -22.66 1.3169
2024-06-20 2023-06-30 13F/A-1 MERCK COM 58933Y105 5,782,918 38,674 0.67 667,291 9.19 1.5527
2023-08-04 2023-06-30 13F MERCK COM 58933Y105 5,782,918 38,674 667,291 1.5527
2024-06-20 2023-03-31 13F/A-1 MERCK COM 58933Y105 5,744,244 578,392 11.20 611,130 6.63 1.5295
2023-04-28 2023-03-31 13F MERCK COM 58933Y105 5,744,244 578,392 611,130 1.5295
2024-06-20 2022-12-31 13F/A-1 MERCK COM 58933Y105 5,165,852 481,739 10.28 573,151 42.08 1.5586
2023-02-10 2022-12-31 13F MERCK COM 58933Y105 5,165,852 481,739 573,151 1.5586
2022-11-10 2022-09-30 13F MERCK COM 58933Y105 4,684,113 1,797,177 62.25 403,396 52.36 1.2010
2022-08-05 2022-06-30 13F MERCK COM 58933Y105 2,886,936 1,969,911 214.82 264,760 248.29 0.8322
2022-05-04 2022-03-31 13F MERCK COM 58933Y105 917,025 -349,205 -27.58 76,017 -21.67 0.1944
2022-02-10 2021-12-31 13F/A-1 MERCK COM 58933Y105 1,266,230 -266,709 -17.40 97,044 -16.44 0.2131
2022-02-08 2021-12-31 13F MERCK COM 58933Y105 1,266,230 -266,709 97,044 0.0699
2021-11-15 2021-09-30 13F MERCK COM 58933Y105 1,532,939 -152,555 -9.05 116,143 -11.41 0.2617
2021-08-10 2021-06-30 13F MERCK COM 58933Y105 1,685,494 472,069 38.90 131,098 40.14 0.2871
2021-05-06 2021-03-31 13F MERCK & CO. COM 58933Y105 1,213,425 155,899 14.74 93,549 8.14 0.2127
2021-02-10 2020-12-31 13F MERCK & CO. COM 58933Y105 1,057,526 -31,134 -2.86 86,506 -4.21 0.2108
2020-10-21 2020-09-30 13F MERCK & CO. COM 58933Y105 1,088,660 -108,176 -9.04 90,304 -2.43 0.2410
2020-08-10 2020-06-30 13F MERCK & CO. COM 58933Y105 1,196,836 -79,087 -6.20 92,551 -5.78 0.2505
2020-05-13 2020-03-31 13F MERCK & CO. COM 58933Y105 1,275,923 -1,332,912 -51.09 98,233 -58.60 0.3120
2020-02-18 2019-12-31 13F MERCK COM 58933Y105 2,608,835 49,302 1.93 237,274 10.12 0.5733
2019-11-13 2019-09-30 13F MERCK COM 58933Y105 2,559,533 -117,187 -4.38 215,462 -4.02 0.5373
2019-08-13 2019-06-30 13F MERCK COM 58933Y105 2,676,720 -344,009 -11.39 224,483 -10.65 0.4985
2019-05-14 2019-03-31 13F MERCK COM 58933Y105 3,020,729 -152,502 -4.81 251,234 5.03 0.5444
2019-02-12 2018-12-31 13F MERCK COM 58933Y105 3,173,231 -129,648 -3.93 239,198 2.09 0.5678
2018-11-20 2018-09-30 13F/A-1 MERCK COM 58933Y105 3,302,879 -149,373 -4.33 234,306 11.80 0.4367
2018-11-13 2018-09-30 13F MERCK COM 58933Y105 3,302,879 -149,373 234,306
2018-08-09 2018-06-30 13F MERCK COM 58933Y105 3,452,252 339,978 10.92 209,569 23.61 0.4027
2018-05-15 2018-03-31 13F MERCK COM 58933Y105 3,112,274 -1,388,867 -30.86 169,540 -33.15 0.3362
2018-02-12 2017-12-31 13F MERCK COM 58933Y105 4,501,141 -414,541 -8.43 253,594 -19.43 0.4851
2017-11-14 2017-09-30 13F MERCK COM 58933Y105 4,915,682 4,915,682 314,750 0.5739
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.