Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionRegions Financial Corp
Latest Disclosed Ownership1,317,370 shares
Latest Disclosed Value $ 158,466,437
Regions Financial Corp reports 3.11% increase in ownership of MRK / Merck & Co., Inc.

On May 5, 2026 - Regions Financial Corp filed a 13F-HR form disclosing ownership of 1,317,370 shares of Merck & Co., Inc. (MX:MRK) valued at $158,466,437 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 27, 2026 disclosing 1,277,678 shares of Merck & Co., Inc.. This represents a change in shares of 3.11% 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)
2026-05-05 2026-03-31 13F MERCK COM 58933Y105 1,317,370 39,692 3.11 158,466 17.83 1.0289
2026-01-27 2025-12-31 13F MERCK COM 58933Y105 1,277,678 -5,809 -0.45 134,488 24.85 0.8609
2025-11-19 2025-09-30 13F/A-1 MERCK COM 58933Y105 1,283,487 -24,516 -1.87 107,723 4.04 0.7016
2025-11-19 2025-09-30 13F MERCK COM 58933Y105 1,283,487 -24,516 107,723 0.6202
2025-07-29 2025-06-30 13F MERCK COM 58933Y105 1,308,003 -27,088 -2.03 103,542 -13.60 0.7130
2025-05-08 2025-03-31 13F MERCK COM 58933Y105 1,335,091 -97,729 -6.82 119,838 -15.93 0.8929
2025-02-14 2024-12-31 13F Merck COM 58933Y105 1,432,820 14,994 1.06 142,537 -11.47 1.0468
2024-11-14 2024-09-30 13F Merck COM 58933Y105 1,417,826 30,806 2.22 161,008 -6.23 1.1586
2024-07-31 2024-06-30 13F Merck COM 58933Y105 1,387,020 -29,009 -2.05 171,713 -8.10 1.3053
2024-04-23 2024-03-31 13F Merck COM 58933Y105 1,416,029 -29,941 -2.07 186,845 18.53 1.4181
2024-02-06 2023-12-31 13F Merck COM 58933Y105 1,445,970 -11,517 -0.79 157,640 5.06 1.2985
2023-11-01 2023-09-30 13F Merck COM 58933Y105 1,457,487 -9,384 -0.64 150,048 -11.35 1.3494
2023-08-09 2023-06-30 13F Merck COM 58933Y105 1,466,871 -40,081 -2.66 169,262 105,688.75 1.4624
2023-05-12 2023-03-31 13F Merck COM 58933Y105 1,506,952 -144,712 -8.76 160 -12.57 1.4390
2023-02-06 2022-12-31 13F Merck COM 58933Y105 1,651,664 -20,456 -1.22 183 -99.87 1.6845
2022-11-03 2022-09-30 13F Merck COM 58933Y105 1,672,120 -15,115 -0.90 144,003 -6.39 1.4518
2022-07-25 2022-06-30 13F Merck COM 58933Y105 1,687,235 -47,445 -2.74 153,825 8.08 1.4630
2022-04-25 2022-03-31 13F Merck COM 58933Y105 1,734,680 234,766 15.65 142,330 23.82 1.1487
2022-01-31 2021-12-31 13F Merck COM 58933Y105 1,499,914 -3,284 -0.22 114,953 1.81 0.8962
2021-11-04 2021-09-30 13F Merck COM 58933Y105 1,503,198 -3,669 -0.24 112,905 -3.66 0.9758
2021-07-27 2021-06-30 13F Merck COM 58933Y105 1,506,867 -24,817 -1.62 117,189 -0.75 1.0131
2021-06-02 2021-03-31 13F Merck COM 58933Y105 1,531,684 2,879 0.19 118,077 -5.58 1.0695
2021-02-05 2020-12-31 13F Merck COM 58933Y105 1,528,805 869 0.06 125,056 -1.33 1.2053
2020-10-15 2020-09-30 13F Merck COM 58933Y105 1,527,936 -27,396 -1.76 126,742 5.38 1.3824
2020-07-27 2020-06-30 13F Merck COM 58933Y105 1,555,332 21,650 1.41 120,274 1.93 1.3997
2020-04-29 2020-03-31 13F Merck COM 58933Y105 1,533,682 -19,740 -1.27 118,001 -16.48 1.5703
2020-02-03 2019-12-31 13F Merck COM 58933Y105 1,553,422 -41,206 -2.58 141,284 5.25 1.4820
2019-10-24 2019-09-30 13F Merck COM 58933Y105 1,594,628 -15,258 -0.95 134,236 -0.56 1.4906
2019-07-19 2019-06-30 13F Merck COM 58933Y105 1,609,886 -27,459 -1.68 134,989 -0.87 1.5229
2019-04-19 2019-03-31 13F MERCK COM 58933Y105 1,637,345 -108,269 -6.20 136,178 2.10 1.5679
2019-01-28 2018-12-31 13F MERCK COM 58933Y105 1,745,614 -115,054 -6.18 133,382 1.05 1.6671
2018-10-22 2018-09-30 13F MERCK COM 58933Y105 1,860,668 -27,163 -1.44 131,996 15.19 1.4236
2018-07-26 2018-06-30 13F MERCK COM 58933Y105 1,887,831 31,444 1.69 114,591 13.33 1.2939
2018-04-18 2018-03-31 13F Merck COM 58933Y105 1,856,387 24,128 1.32 101,117 -1.92 1.1347
2018-01-18 2017-12-31 13F Merck COM 58933Y105 1,832,259 -24,318 -1.31 103,101 -13.27 1.1155
2017-10-23 2017-09-30 13F MERCK COMMON STOCK 58933Y105 1,856,577 31,682 1.74 118,876 1.64 1.3503
2017-07-31 2017-06-30 13F MERCK COMMON STOCK 58933Y105 1,824,895 -41,257 -2.21 116,958 -1.36 1.3727
2017-05-02 2017-03-31 13F MERCK COMMON STOCK 58933Y105 1,866,152 7,322 0.39 118,575 8.36 1.4038
2017-02-03 2016-12-31 13F MERCK COMMON STOCK 58933Y105 1,858,830 11,694 0.63 109,429 -5.08 1.3397
2016-10-28 2016-09-30 13F MERCK COMMON STOCK 58933Y105 1,847,136 -30,522 -1.63 115,280 6.57 1.4859
2016-07-26 2016-06-30 13F MERCK COMMON STOCK 58933Y105 1,877,658 -33,440 -1.75 108,173 6.98 1.4026
2016-05-02 2016-03-31 13F MERCK COMMON STOCK 58933Y105 1,911,098 25,887 1.37 101,117 1.55 1.3405
2016-01-29 2015-12-31 13F MERCK COMMON STOCK 58933Y105 1,885,211 20,611 1.11 99,577 8.13 1.3358
2015-10-20 2015-09-30 13F MERCK COMMON STOCK 58933Y105 1,864,600 -64,711 -3.35 92,093 -16.15 1.3122
2015-07-14 2015-06-30 13F MERCK COMMON STOCK 58933Y105 1,929,311 -31,796 -1.62 109,836 -2.56 1.4581
2015-04-23 2015-03-31 13F MERCK COMMON STOCK 58933Y105 1,961,107 32,890 1.71 112,724 2.94 1.4487
2015-01-21 2014-12-31 13F MERCK COMMON STOCK 58933Y105 1,928,217 -73,014 -3.65 109,503 -7.70 1.4197
2014-10-27 2014-09-30 13F MERCK COMMON STOCK 58933Y105 2,001,231 12,851 0.65 118,633 3.13 1.4799
2014-07-23 2014-06-30 13F MERCK COMMON STOCK 58933Y105 1,988,380 -21,829 -1.09 115,029 0.80 1.4091
2014-04-17 2014-03-31 13F MERCK COMMON STOCK 58933Y105 2,010,209 -34,232 -1.67 114,119 11.53 1.4478
2014-01-27 2013-12-31 13F MERCK COMMON STOCK 58933Y105 2,044,441 32,025 1.59 102,325 6.80 1.2644
2013-10-18 2013-09-30 13F MERCK COMMON STOCK 58933Y105 2,012,416 -20,901 -1.03 95,810 1.44 1.2662
2013-08-02 2013-06-30 13F MERCK COM 58933Y105 2,033,317 2,033,317 94,449 1.2879
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.