Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionZacks Investment Management
Latest Disclosed Ownership1,085,250 shares
Latest Disclosed Value $ 130,544,741
Zacks Investment Management reports 0.38% increase in ownership of MRK / Merck & Co., Inc.

On May 14, 2026 - Zacks Investment Management filed a 13F-HR form disclosing ownership of 1,085,250 shares of Merck & Co., Inc. (MX:MRK) valued at $130,544,741 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 1,081,122 shares of Merck & Co., Inc.. This represents a change in shares of 0.38% 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)
2026-05-14 2026-03-31 13F MERCK COM 58933Y105 1,085,250 4,128 0.38 130,545 14.72 0.7242
2026-02-17 2025-12-31 13F MERCK COM 58933Y105 1,081,122 52,402 5.09 113,799 31.80 0.8941
2025-11-14 2025-09-30 13F MERCK COM 58933Y105 1,028,720 15,557 1.54 86,341 7.65 0.6878
2025-08-12 2025-06-30 13F MERCK COM 58933Y105 1,013,163 -1,149 -0.11 80,202 -11.91 0.6861
2025-05-14 2025-03-31 13F MERCK COM 58933Y105 1,014,312 39,854 4.09 91,045 -6.08 0.8500
2025-02-13 2024-12-31 13F MERCK COM 58933Y105 974,458 -217,260 -18.23 96,939 -28.37 0.8974
2024-11-14 2024-09-30 13F MERCK COM 58933Y105 1,191,718 115,880 10.77 135,332 1.61 1.1740
2024-08-14 2024-06-30 13F MERCK COM 58933Y105 1,075,838 165,587 18.19 133,189 10.89 1.4993
2024-05-15 2024-03-31 13F MERCK COM 58933Y105 910,251 97,718 12.03 120,108 35.59 1.2808
2024-02-14 2023-12-31 13F MERCK COM 58933Y105 812,533 -51,593 -5.97 88,582 -0.43 1.0912
2023-11-14 2023-09-30 13F MERCK COM 58933Y105 864,126 -306,414 -26.18 88,962 -34.14 1.1522
2023-08-15 2023-06-30 13F/A-1 MERCK COM 58933Y105 1,170,540 29,274 2.57 135,069 11.24 1.6957
2023-08-15 2023-06-30 13F MERCK COM 58933Y105 1,095,908 126,457
2023-05-15 2023-03-31 13F MERCK COM 58933Y105 1,141,266 27,806 2.50 121,419 -1.72 1.6274
2023-02-14 2022-12-31 13F MERCK COM 58933Y105 1,113,460 49,763 4.68 123,538 34.86 1.7247
2022-11-14 2022-09-30 13F MERCK COM 58933Y105 1,063,697 28,056 2.71 91,606 -2.98 1.4642
2022-08-15 2022-06-30 13F MERCK COM 58933Y105 1,035,641 62,538 6.43 94,420 18.26 1.4406
2022-05-13 2022-03-31 13F MERCK COM 58933Y105 973,103 63,445 6.97 79,843 14.53 1.1080
2022-02-15 2021-12-31 13F MERCK COM 58933Y105 909,658 259,858 39.99 69,716 42.81 0.9803
2021-11-15 2021-09-30 13F MERCK COM 58933Y105 649,800 -182,807 -21.96 48,817 -24.61 0.7706
2021-08-16 2021-06-30 13F MERCK COM 58933Y105 832,607 -64,901 -7.23 64,752 -6.41 1.0480
2021-05-17 2021-03-31 13F MERCK & CO. COM 58933Y105 897,508 7,884 0.89 69,189 -4.92 1.2314
2021-02-16 2020-12-31 13F MERCK & CO. COM 58933Y105 889,624 -144,044 -13.94 72,772 -15.13 1.3430
2020-11-16 2020-09-30 13F MERCK & CO. COM 58933Y105 1,033,668 4,213 0.41 85,743 7.71 1.7374
2020-08-14 2020-06-30 13F MERCK & CO. COM 58933Y105 1,029,455 35,195 3.54 79,608 4.07 1.7505
2020-05-15 2020-03-31 13F MERCK & CO. COM 58933Y105 994,260 -431 -0.04 76,498 -15.44 1.8763
2020-02-14 2019-12-31 13F MERCK COM 58933Y105 994,691 17,556 1.80 90,467 9.98 1.6945
2019-11-14 2019-09-30 13F MERCK COM 58933Y105 977,135 19,051 1.99 82,255 2.39 1.6484
2019-08-14 2019-06-30 13F MERCK COM 58933Y105 958,084 -28,594 -2.90 80,335 1.66 1.6481
2019-05-15 2019-03-31 13F MERCK COM 58933Y105 986,678 -323,906 -24.71 79,020 -21.09 1.6949
2019-02-14 2018-12-31 13F MERCK COM 58933Y105 1,310,584 -101,251 -7.17 100,142 -0.01 2.4151
2018-11-14 2018-09-30 13F MERCK COM 58933Y105 1,411,835 39,075 2.85 100,156 20.20 2.0903
2018-08-14 2018-06-30 13F MERCK COM 58933Y105 1,372,760 22,666 1.68 83,327 13.31 1.8133
2018-05-14 2018-03-31 13F MERCK COM 58933Y105 1,350,094 11,712 0.88 73,540 -2.35 1.6332
2018-02-14 2017-12-31 13F MERCK COM 58933Y105 1,338,382 895 0.07 75,311 -12.06 1.6420
2017-11-14 2017-09-30 13F MERCK COM 58933Y105 1,337,487 10,340 0.78 85,639 0.68 2.0054
2017-08-14 2017-06-30 13F MERCK COM 58933Y105 1,327,147 66,556 5.28 85,057 6.19 2.1064
2017-05-15 2017-03-31 13F MERCK COM 58933Y105 1,260,591 122,890 10.80 80,098 19.59 2.0372
2017-02-13 2016-12-31 13F MERCK COM 58933Y105 1,137,701 -60,498 -5.05 66,976 -10.44 1.9223
2016-11-14 2016-09-30 13F MERCK COM 58933Y105 1,198,199 312,643 35.30 74,780 46.58 2.1154
2016-08-15 2016-06-30 13F MERCK COM 58933Y105 885,556 26,756 3.12 51,017 12.28 1.5558
2016-05-12 2016-03-31 13F MERCK & CO INC COM 58933Y105 858,800 51,683 6.40 45,439 6.58 1.4415
2016-02-16 2015-12-31 13F MERCK & CO INC COM 58933Y105 807,117 -34,042 -4.05 42,632 2.62 1.3935
2015-11-12 2015-09-30 13F MERCK & CO INC COM 58933Y105 841,159 -19,177 -2.23 41,545 -15.18 1.4477
2015-08-12 2015-06-30 13F MERCK & CO INC COM 58933Y105 860,336 -11,533 -1.32 48,979 -2.27 1.5529
2015-05-12 2015-03-31 13F MERCK & CO INC COM 58933Y105 871,869 40,465 4.87 50,115 6.14 1.5856
2015-02-13 2014-12-31 13F MERCK & CO INC COM 58933Y105 831,404 45,664 5.81 47,215 1.45 1.5305
2014-11-13 2014-09-30 13F MERCK & CO INC COM 58933Y105 785,740 52,651 7.18 46,539 9.77 1.6217
2014-08-12 2014-06-30 13F MERCK & CO INC COM 58933Y105 733,089 36,684 5.27 42,398 7.24 1.5058
2014-05-13 2014-03-31 13F MERCK & CO INC COM 58933Y105 696,405 54,877 8.55 39,535 23.13 1.4645
2014-02-13 2013-12-31 13F MERCK & CO INC COM 58933Y105 641,528 144,328 29.03 32,108 35.64 1.2660
2013-11-14 2013-09-30 13F/A-1 MERCK & CO INC COM 58933Y105 497,200 31,567 6.78 23,671 9.44 1.0232
2013-11-13 2013-09-30 13F MERCK & CO INC COM 58933Y105 160,566 23,671
2013-08-13 2013-06-30 13F MERCK & CO INC COM 58933Y105 465,633 465,633 21,629 0.9926
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.