Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionRitholtz Wealth Management
Latest Disclosed Ownership44,966 shares
Latest Disclosed Value $ 5,408,962
Ritholtz Wealth Management reports 20.84% increase in ownership of MRK / Merck & Co., Inc.

On April 20, 2026 - Ritholtz Wealth Management filed a 13F-HR form disclosing ownership of 44,966 shares of Merck & Co., Inc. (MX:MRK) valued at $5,408,962 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 23, 2026 disclosing 37,211 shares of Merck & Co., Inc.. This represents a change in shares of 20.84% 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)
2026-04-20 2026-03-31 13F MERCK COM 58933Y105 44,966 7,755 20.84 5,409 38.10 0.0938
2026-01-23 2025-12-31 13F MERCK COM 58933Y105 37,211 10,305 38.30 3,917 73.43 0.0715
2025-10-28 2025-09-30 13F MERCK COM 58933Y105 26,906 410 1.55 2,258 7.68 0.0439
2025-07-28 2025-06-30 13F MERCK COM 58933Y105 26,496 -14,311 -35.07 2,097 -42.74 0.0463
2025-04-17 2025-03-31 13F MERCK COM 58933Y105 40,807 -6,900 -14.46 3,663 -22.82 0.1094
2025-01-15 2024-12-31 13F MERCK COM 58933Y105 47,707 -2,286 -4.57 4,746 -16.42 0.1394
2024-10-10 2024-09-30 13F MERCK COM 58933Y105 49,993 -109 -0.22 5,677 -8.47 0.1711
2024-08-01 2024-06-30 13F MERCK COM 58933Y105 50,102 978 1.99 6,203 -4.30 0.2047
2024-04-24 2024-03-31 13F MERCK COM 58933Y105 49,124 636 1.31 6,482 22.61 0.2236
2024-01-18 2023-12-31 13F MERCK COM 58933Y105 48,488 -4,826 -9.05 5,286 -3.68 0.2051
2023-10-13 2023-09-30 13F MERCK COM 58933Y105 53,314 1,756 3.41 5,489 -7.75 0.2464
2023-07-17 2023-06-30 13F MERCK COM 58933Y105 51,558 951 1.88 5,949 10.49 0.2676
2023-04-20 2023-03-31 13F MERCK COM 58933Y105 50,607 -1,106 -2.14 5,384 -6.15 0.2684
2023-01-19 2022-12-31 13F MERCK COM 58933Y105 51,713 -1,896 -3.54 5,738 24.26 0.3203
2022-10-19 2022-09-30 13F MERCK COM 58933Y105 53,609 26,883 100.59 4,617 89.45 0.2452
2022-07-15 2022-06-30 13F MERCK COM 58933Y105 26,726 5,985 28.86 2,437 43.18 0.1535
2022-04-14 2022-03-31 13F MERCK COM 58933Y105 20,741 4,983 31.62 1,702 40.89 0.1150
2022-01-18 2021-12-31 13F MERCK COM 58933Y105 15,758 1,578 11.13 1,208 13.43 0.0751
2021-10-14 2021-09-30 13F MERCK COM 58933Y105 14,180 1,238 9.57 1,065 5.76 0.0738
2021-07-20 2021-06-30 13F MERCK COM 58933Y105 12,942 1,883 17.03 1,007 18.05 0.0725
2021-05-12 2021-03-31 13F MERCK & CO. COM 58933Y105 11,059 1,996 22.02 853 15.11 0.0710
2021-01-19 2020-12-31 13F MERCK & CO. COM 58933Y105 9,063 -427 -4.50 741 -5.84 0.0709
2020-10-23 2020-09-30 13F MERCK & CO. COM 58933Y105 9,490 466 5.16 787 12.75 0.0884
2020-07-15 2020-06-30 13F MERCK & CO. COM 58933Y105 9,024 3,959 78.16 698 78.97 0.0899
2020-04-09 2020-03-31 13F MERCK & CO. COM 58933Y105 5,065 -2,153 -29.83 390 -40.55 0.0625
2020-01-17 2019-12-31 13F MERCK COM 58933Y105 7,218 429 6.32 656 14.89 0.0957
2019-10-17 2019-09-30 13F MERCK COM 58933Y105 6,789 124 1.86 571 2.15 0.0927
2019-07-15 2019-06-30 13F MERCK COM 58933Y105 6,665 -148 -2.17 559 -1.41 0.0955
2019-04-12 2019-03-31 13F MERCK COM 58933Y105 6,813 322 4.96 567 14.31 0.1039
2019-01-18 2018-12-31 13F MERCK COM 58933Y105 6,491 398 6.53 496 14.81 0.1124
2018-10-12 2018-09-30 13F MERCK COM 58933Y105 6,093 32 0.53 432 17.39 0.1094
2018-07-12 2018-06-30 13F MERCK COM 58933Y105 6,061 1,453 31.53 368 46.61 0.1000
2018-04-17 2018-03-31 13F MERCK COM 58933Y105 4,608 -128 -2.70 251 -5.64 0.0717
2018-01-23 2017-12-31 13F MERCK COM 58933Y105 4,736 4,736 266 0.0788
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.