Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionAureus Asset Management, LLC
Latest Disclosed Ownership11,787 shares
Latest Disclosed Value $ 1,417,858
Aureus Asset Management, LLC reports 0.85% increase in ownership of MRK / Merck & Co., Inc.

On May 13, 2026 - Aureus Asset Management, LLC filed a 13F-HR form disclosing ownership of 11,787 shares of Merck & Co., Inc. (MX:MRK) valued at $1,417,858 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 11,688 shares of Merck & Co., Inc.. This represents a change in shares of 0.85% 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)
2026-05-13 2026-03-31 13F Merck Stock 58933Y105 11,787 99 0.85 1,418 15.20 0.0944
2026-02-17 2025-12-31 13F Merck Stock 58933Y105 11,688 1,414 13.76 1,230 42.69 0.0784
2025-11-17 2025-09-30 13F Merck Stock 58933Y105 10,274 -1,707 -14.25 862 -9.07 0.0561
2025-08-14 2025-06-30 13F Merck Stock 58933Y105 11,981 -46,288 -79.44 948 -81.87 0.0607
2025-05-15 2025-03-31 13F Merck Stock 58933Y105 58,269 14,704 33.75 5,230 20.70 0.3665
2025-02-14 2024-12-31 13F Merck Stock 58933Y105 43,565 -7,432 -14.57 4,334 -25.18 0.2800
2024-11-14 2024-09-30 13F Merck Stock 58933Y105 50,997 9,130 21.81 5,791 11.73 0.3788
2024-08-13 2024-06-30 13F Merck Stock 58933Y105 41,867 8,038 23.76 5,183 16.13 0.3623
2024-05-13 2024-03-31 13F Merck Stock 58933Y105 33,829 22,189 190.63 4,464 251.97 0.3047
2024-02-14 2023-12-31 13F Merck Stock 58933Y105 11,640 256 2.25 1,269 8.28 0.0928
2023-11-13 2023-09-30 13F Merck Stock 58933Y105 11,384 1,062 10.29 1,172 -1.68 0.0941
2023-08-11 2023-06-30 13F Merck Stock 58933Y105 10,322 106 1.04 1,191 9.67 0.0893
2023-05-12 2023-03-31 13F Merck Stock 58933Y105 10,216 -10 -0.10 1,087 -4.23 0.0860
2023-02-14 2022-12-31 13F Merck Stock 58933Y105 10,226 -186 -1.79 1,135 26.42 0.0980
2022-11-14 2022-09-30 13F Merck Stock 58933Y105 10,412 -1,881 -15.30 897 -19.98 0.0781
2022-08-15 2022-06-30 13F Merck Stock 58933Y105 12,293 430 3.62 1,121 15.21 0.0905
2022-05-12 2022-03-31 13F Merck Stock 58933Y105 11,863 310 2.68 973 9.94 0.0647
2022-02-14 2021-12-31 13F Merck Stock 58933Y105 11,553 771 7.15 885 9.26 0.0546
2021-11-12 2021-09-30 13F Merck Stock 58933Y105 10,782 270 2.57 810 -0.98 0.0533
2021-08-16 2021-06-30 13F Merck Stock 58933Y105 10,512 207 2.01 818 3.02 0.0526
2021-05-14 2021-03-31 13F Merck Stock 58933Y105 10,305 -5,756 -35.84 794 -39.57 0.0616
2021-02-16 2020-12-31 13F Merck Stock 58933Y105 16,061 610 3.95 1,314 2.50 0.1107
2020-11-13 2020-09-30 13F Merck Stock 58933Y105 15,451 -2,220 -12.56 1,282 -6.15 0.1213
2020-08-11 2020-06-30 13F Merck Stock 58933Y105 17,671 -1,473 -7.69 1,366 -7.26 0.1490
2020-05-14 2020-03-31 13F Merck Stock 58933Y105 19,144 -1,043 -5.17 1,473 -19.77 0.2043
2020-02-12 2019-12-31 13F Merck Stock 58933Y105 20,187 1,466 7.83 1,836 16.50 0.2051
2019-11-12 2019-09-30 13F Merck Stock 58933Y105 18,721 0 0.00 1,576 0.38 0.1962
2019-08-14 2019-06-30 13F Merck Stock 58933Y105 18,721 -2,470 -11.66 1,570 -10.90 0.1933
2019-05-13 2019-03-31 13F Merck Stock 58933Y105 21,191 -80 -0.38 1,762 8.43 0.2334
2019-02-13 2018-12-31 13F Merck Stock 58933Y105 21,271 632 3.06 1,625 11.00 0.2555
2018-11-14 2018-09-30 13F Merck Stock 58933Y105 20,639 0 0.00 1,464 16.84 0.1861
2018-08-13 2018-06-30 13F Merck Stock 58933Y105 20,639 5,398 35.42 1,253 50.96 0.1722
2018-05-15 2018-03-31 13F Merck Stock 58933Y105 15,241 988 6.93 830 3.49 0.1247
2018-02-14 2017-12-31 13F Merck Stock 58933Y105 14,253 -1,481 -9.41 802 -20.36 0.1242
2017-11-13 2017-09-30 13F MERCK & CO INC COM Stock 58933Y105 15,734 7,050 81.18 1,007 80.79 0.1592
2017-08-14 2017-06-30 13F MERCK & CO INC COM Stock 58933Y105 8,684 -220 -2.47 557 -2.96 0.0937
2017-05-12 2017-03-31 13F MERCK & CO INC COM Stock 58933Y105 8,904 4,050 83.44 574 100.70 0.0996
2017-02-14 2016-12-31 13F MERCK & CO INC COM Stock 58933Y105 4,854 -1,262 -20.63 286 -25.13 0.0560
2016-11-14 2016-09-30 13F MERCK & CO INC COM Stock 58933Y105 6,116 1,391 29.44 382 40.44 0.0764
2016-08-15 2016-06-30 13F/A-1 MERCK COM 58933Y105 4,725 4,725 0.00 272 0.0586
2016-08-15 2016-06-30 13F STARBUCKS COM 58933Y105 11,168 638
2016-05-13 2016-03-31 13F MERCK COM 58933Y105 0 -218,223 -100.00 0 -100.00
2016-02-16 2015-12-31 13F MERCK COM 58933Y105 218,223 -2,942 -1.33 11,527 5.53 2.5882
2015-11-13 2015-09-30 13F MERCK COM 58933Y105 221,165 -2,679 -1.20 10,923 -14.28 2.7166
2015-08-12 2015-06-30 13F MERCK COM 58933Y105 223,844 15,909 7.65 12,743 6.62 2.6788
2015-05-13 2015-03-31 13F MERCK COM 58933Y105 207,935 4,757 2.34 11,952 3.59 2.7481
2015-02-12 2014-12-31 13F MERCK COM 58933Y105 203,178 -3,449 -1.67 11,538 -5.80 2.8054
2014-11-14 2014-09-30 13F MERCK COM 58933Y105 206,627 2,790 1.37 12,249 3.88 3.0736
2014-08-08 2014-06-30 13F MERCK COM 58933Y105 203,837 12,582 6.58 11,792 8.60 2.9478
2014-05-06 2014-03-31 13F MERCK COM 58933Y105 191,255 7,518 4.09 10,858 18.07 2.7893
2014-01-13 2013-12-31 13F MERCK COM 58933Y105 183,737 27,590 17.67 9,196 23.70 2.4903
2013-11-14 2013-09-30 13F MERCK COM 58933Y105 156,147 5,253 3.48 7,434 6.06 2.5427
2013-08-08 2013-06-30 13F MERCK COM 58933Y105 150,894 150,894 7,009 2.5087
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.