Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionNinety One UK Ltd
Latest Disclosed Ownership96,901 shares
Latest Disclosed Value $ 11,656,218
Ninety One UK Ltd reports 18.50% decrease in ownership of MRK / Merck & Co., Inc.

On April 24, 2026 - Ninety One UK Ltd filed a 13F-HR form disclosing ownership of 96,901 shares of Merck & Co., Inc. (MX:MRK) valued at $11,656,218 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 27, 2026 disclosing 118,890 shares of Merck & Co., Inc.. This represents a change in shares of -18.50% 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.

Upgrade to unlock premium data and export to Excel .

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)
2026-04-24 2026-03-31 13F Merck Common Stock 58933Y105 96,901 -21,989 -18.50 11,656 -6.86 0.0270
2026-01-27 2025-12-31 13F Merck Common Stock 58933Y105 118,890 -14,696 -11.00 12,514 11.62 0.0268
2025-11-13 2025-09-30 13F/A-1 Merck Common Stock 58933Y105 133,586 42,007 45.87 11,212 54.66 0.0242
2025-10-21 2025-09-30 13F Merck Common Stock 58933Y105 133,586 42,007 11,212 0.0247
2025-07-18 2025-06-30 13F Merck Common Stock 58933Y105 91,579 34,884 61.53 7,249 42.47 0.0170
2025-04-30 2025-03-31 13F MERCK Common Stock 58933Y105 56,695 11,708 26.03 5,089 13.70 0.0142
2025-01-27 2024-12-31 13F MERCK Common Stock 58933Y105 44,987 0 0.00 4,475 -12.39 0.0120
2024-11-12 2024-09-30 13F MERCK Common Stock 58933Y105 44,987 0 0.00 5,109 -8.28 0.0136
2024-07-22 2024-06-30 13F MERCK Common Stock 58933Y105 44,987 -21,631 -32.47 5,569 -36.64 0.0154
2024-04-25 2024-03-31 13F MERCK Common Stock 58933Y105 66,618 -947 -1.40 8,790 19.35 0.0247
2024-01-31 2023-12-31 13F MERCK Common Stock 58933Y105 67,565 67,565 7,366 0.0219
2022-02-11 2021-12-31 13F MERCK Common Stock 58933Y105 0 -1,332,411 -100.00 0 -100.00
2021-11-02 2021-09-30 13F MERCK Common Stock 58933Y105 1,332,411 12,730 0.96 100,077 -2.49 0.2555
2021-08-12 2021-06-30 13F MERCK Common Stock 58933Y105 1,319,681 685,061 107.95 102,632 109.78 0.2659
2021-05-07 2021-03-31 13F MERCK Common Stock 58933Y105 634,620 -12,492 -1.93 48,923 -7.58 0.1391
2021-02-05 2020-12-31 13F MERCK Common Stock 58933Y105 647,112 -280,700 -30.25 52,934 -31.22 0.1628
2020-11-12 2020-09-30 13F MERCK Common Stock 58933Y105 927,812 -2,495,178 -72.89 76,962 -70.92 0.2783
2020-09-04 2020-06-30 13F/A-1 MERCK Common Stock 58933Y105 3,422,990 -83,937 -2.39 264,700 -1.90 0.9379
2020-08-14 2020-06-30 13F MERCK Common Stock 58933Y105 3,865,313 358,386 351,550 1,165,988.3890
2020-05-12 2020-03-31 13F MERCK Common Stock 58933Y105 3,506,927 -358,386 -9.27 269,823 -23.25 1.1350
2020-02-07 2019-12-31 13F MERCK Common Stock 58933Y105 3,865,313 -128,262 -3.21 351,550 4.57 1.1660
2019-11-14 2019-09-30 13F MERCK Common Stock 58933Y105 3,993,575 -752,721 -15.86 336,179 -15.53 1.3085
2019-07-30 2019-06-30 13F MERCK Common Stock 58933Y105 4,746,296 18,736 0.40 397,977 1.22 1.5144
2019-04-24 2019-03-31 13F MERCK Common Stock 58933Y105 4,727,560 -285,468 -5.69 393,191 2.65 1.5577
2019-02-08 2018-12-31 13F MERCK Common Stock 58933Y105 5,013,028 992,770 24.69 383,045 34.31 1.6518
2018-11-13 2018-09-30 13F MERCK Common Stock 58933Y105 4,020,258 924,250 29.85 285,197 51.76 1.0640
2018-08-10 2018-06-30 13F MERCK Common Stock 58933Y105 3,096,008 3,025,967 4,320.28 187,928 4,826.03 0.9336
2018-05-14 2018-03-31 13F MERCK Common Stock 58933Y105 70,041 -88 -0.13 3,815 -3.32 0.0204
2018-02-13 2017-12-31 13F MERCK Common Stock 58933Y105 70,129 -3,078 -4.20 3,946 -15.81 0.0162
2017-11-13 2017-09-30 13F MERCK Common Stock 58933Y105 73,207 -2,418 -3.20 4,687 -3.30 0.0206
2017-08-11 2017-06-30 13F MERCK Common Stock 58933Y105 75,625 -50,094 -39.85 4,847 -39.32 0.0231
2017-05-12 2017-03-31 13F MERCK Common Stock 58933Y105 125,719 9,266 7.96 7,988 16.51 0.0395
2017-02-10 2016-12-31 13F MERCK Common Stock 58933Y105 116,453 719 0.62 6,856 -5.08 0.0358
2016-11-14 2016-09-30 13F MERCK Common Stock 58933Y105 115,734 -1,348 -1.15 7,223 7.09 0.0352
2016-08-12 2016-06-30 13F MERCK Common Stock 58933Y105 117,082 -2,202 -1.85 6,745 6.88 0.0349
2016-05-12 2016-03-31 13F MERCK Common Stock 58933Y105 119,284 -151,088 -55.88 6,311 -55.81 0.0341
2016-02-16 2015-12-31 13F MERCK Common Stock 58933Y105 270,372 -1,847 -0.68 14,281 6.22 0.0815
2015-10-30 2015-09-30 13F MERCK Common Stock 58933Y105 272,219 -7,467 -2.67 13,445 -15.56 0.0844
2015-08-11 2015-06-30 13F MERCK Common Stock 58933Y105 279,686 -41,028 -12.79 15,923 -13.63 0.0908
2015-05-14 2015-03-31 13F MERCK Common Stock 58933Y105 320,714 -95,763 -22.99 18,435 -22.06 0.1077
2015-02-13 2014-12-31 13F MERCK Common Stock 58933Y105 416,477 11,577 2.86 23,652 -1.46 0.1445
2014-11-10 2014-09-30 13F MERCK Common Stock 58933Y105 404,900 9,953 2.52 24,002 5.05 0.1414
2014-08-13 2014-06-30 13F MERCK Common Stock 58933Y105 394,947 -126,467 -24.25 22,848 -22.81 0.1326
2014-05-12 2014-03-31 13F MERCK Common Stock 58933Y105 521,414 17,220 3.42 29,601 17.30 0.2255
2014-02-11 2013-12-31 13F MERCK Common Stock 58933Y105 504,194 -82,598 -14.08 25,235 -9.67 0.1760
2013-11-08 2013-09-30 13F MERCK Common Stock 58933Y105 586,792 -23,867 -3.91 27,937 -1.51 0.2055
2013-08-12 2013-06-30 13F MERCK Common Stock 58933Y105 610,659 610,659 28,365 0.2174
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.