Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionAssenagon Asset Management S.A.
Latest Disclosed Ownership743,214 shares
Latest Disclosed Value $ 89,401,212
Assenagon Asset Management S.A. reports 37.23% increase in ownership of MRK / Merck & Co., Inc.

On April 20, 2026 - Assenagon Asset Management S.A. filed a 13F-HR form disclosing ownership of 743,214 shares of Merck & Co., Inc. (MX:MRK) valued at $89,401,212 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 9, 2026 disclosing 541,572 shares of Merck & Co., Inc.. This represents a change in shares of 37.23% 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 743,214 201,642 37.23 89,401 56.83 0.1357
2026-01-09 2025-12-31 13F MERCK COM 58933Y105 541,572 -4,955,092 -90.15 57,006 -87.64 0.0785
2025-10-07 2025-09-30 13F MERCK COM 58933Y105 5,496,664 3,618,532 192.67 461,335 210.30 0.6309
2025-07-11 2025-06-30 13F MERCK COM 58933Y105 1,878,132 1,391,088 285.62 148,673 240.08 0.2207
2025-04-15 2025-03-31 13F MERCK COM 58933Y105 487,044 -222,494 -31.36 43,717 -38.06 0.0729
2025-01-14 2024-12-31 13F MERCK COM 58933Y105 709,538 -1,440,399 -67.00 70,585 -71.09 0.1138
2024-10-23 2024-09-30 13F MERCK COM 58933Y105 2,149,937 805,571 59.92 244,147 46.69 0.4493
2024-07-18 2024-06-30 13F MERCK COM 58933Y105 1,344,366 -290,538 -17.77 166,433 -22.85 0.3705
2024-04-24 2024-03-31 13F MERCK COM 58933Y105 1,634,904 470,217 40.37 215,726 69.90 0.5106
2024-01-17 2023-12-31 13F MERCK COM 58933Y105 1,164,687 -181,345 -13.47 126,974 -8.37 0.3370
2023-11-06 2023-09-30 13F MERCK COM 58933Y105 1,346,032 817,128 154.49 138,574 127.06 0.4290
2023-07-25 2023-06-30 13F MERCK COM 58933Y105 528,904 -1,227,869 -69.89 61,030 -67.35 0.2111
2023-04-18 2023-03-31 13F MERCK COM 58933Y105 1,756,773 257,964 17.21 186,903 112,492.17 0.6634
2023-01-12 2022-12-31 13F MERCK COM 58933Y105 1,498,809 -1,148,321 -43.38 166 -99.93 0.5998
2022-10-27 2022-09-30 13F MERCK COM 58933Y105 2,647,130 1,901,328 254.94 227,971 235.28 0.8750
2022-07-27 2022-06-30 13F MERCK COM 58933Y105 745,802 -326,773 -30.47 67,995 -22.74 0.2520
2022-04-25 2022-03-31 13F MERCK COM 58933Y105 1,072,575 1,022,576 2,045.19 88,005 2,196.58 0.2445
2022-02-01 2021-12-31 13F MERCK COM 58933Y105 49,999 3,741 8.09 3,832 10.31 0.0111
2021-10-19 2021-09-30 13F MERCK COM 58933Y105 46,258 24,553 113.12 3,474 105.81 0.0111
2021-07-15 2021-06-30 13F MERCK COM 58933Y105 21,705 2,127 10.86 1,688 11.86 0.0057
2021-04-26 2021-03-31 13F MERCK & CO. COM 58933Y105 19,578 1,173 6.37 1,509 0.20 0.0061
2021-02-01 2020-12-31 13F MERCK & CO. COM 58933Y105 18,405 5,870 46.83 1,506 44.81 0.0066
2020-10-07 2020-09-30 13F MERCK & CO. COM 58933Y105 12,535 1,514 13.74 1,040 22.07 0.0058
2020-07-21 2020-06-30 13F MERCK & CO. COM 58933Y105 11,021 -43,301 -79.71 852 -79.62 0.0055
2020-04-17 2020-03-31 13F MERCK & CO. COM 58933Y105 54,322 -2,027,752 -97.39 4,180 -97.79 0.0335
2020-01-17 2019-12-31 13F MERCK COM 58933Y105 2,082,074 1,279,670 159.48 189,365 180.35 1.1911
2019-10-16 2019-09-30 13F MERCK COM 58933Y105 802,404 43,140 5.68 67,546 6.10 0.4522
2019-08-12 2019-06-30 13F MERCK COM 58933Y105 759,264 746,564 5,878.46 63,664 5,928.79 0.4782
2019-04-26 2019-03-31 13F MERCK COM 58933Y105 12,700 -1,100 -7.97 1,056 0.19 0.0099
2019-01-23 2018-12-31 13F MERCK COM 58933Y105 13,800 -1,096,935 -98.76 1,054 -98.66 0.0119
2018-10-29 2018-09-30 13F MERCK COM 58933Y105 1,110,735 870,423 362.21 78,796 440.18 0.7778
2018-07-17 2018-06-30 13F MERCK COM 58933Y105 240,312 240,312 14,587 0.1684
2018-01-25 2017-12-31 13F MERCK COM 58933Y105 0 -729,590 -100.00 0 -100.00
2017-10-18 2017-09-30 13F MERCK COM 58933Y105 729,590 729,590 46,716 0.4338
2017-07-19 2017-06-30 13F MERCK COM 58933Y105 0 -1,172,000 -100.00 0 -100.00
2017-05-04 2017-03-31 13F MERCK COM 58933Y105 1,172,000 1,172,000 74,469 1.5932
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.