Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionM&t Bank Corp
Latest Disclosed Ownership1,453,030 shares
Latest Disclosed Value $ 174,784,968
M&t Bank Corp ownership in MRK / Merck & Co., Inc.

On May 12, 2026 - M&t Bank Corp filed a 13F-HR form disclosing ownership of 1,453,030 shares of Merck & Co., Inc. (MX:MRK) valued at $174,784,968 USD as of March 31, 2026. The entity filed a previous 13F-HR/A on January 30, 2026 disclosing 1,476,206 shares of Merck & Co., Inc.. This represents a change in shares of -1.57% during the quarter.

M&t Bank Corp has a history of taking positions in derivatives of the underlying security (MRK) in the form of stock options. The firm currently holds call options representing 0 of underlying shares valued at $0 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

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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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

MX:MRK / Merck & Co., Inc. Historical Put/Call Ratio
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)
2026-05-12 2026-03-31 13F MERCK COM 58933Y105 1,453,030 -23,176 -1.57 174,785 12.48 0.1417
2026-01-30 2025-12-31 13F/A-1 MERCK COM 58933Y105 1,476,206 -22,631 -1.51 155,386 23.52 0.4989
2026-01-28 2025-12-31 13F MERCK COM 58933Y105 45,898 -1,452,939 5,115 0.0030
2025-11-14 2025-09-30 13F MERCK COM 58933Y105 1,498,837 -112,150 -6.96 125,797 -1.36 0.4230
2025-08-13 2025-06-30 13F MERCK COM 58933Y105 1,610,987 -386,932 -19.37 127,526 -28.89 0.4382
2025-04-30 2025-03-31 13F MERCK COM 58933Y105 1,997,919 -149,894 -6.98 179,333 -16.07 0.6533
2025-02-06 2024-12-31 13F MERCK COM 58933Y105 2,147,813 -56,741 -2.57 213,664 -14.65 0.7161
2024-11-19 2024-09-30 13F/A-1 MERCK COM 58933Y105 2,204,554 -73,412 -3.22 250,349 -11.23 0.8232
2024-11-15 2024-09-30 13F MERCK COM 58933Y105 2,204,554 -73,412 250,349 0.1505
2024-07-31 2024-06-30 13F MERCK COM 58933Y105 2,277,966 11,820 0.52 282,014 -5.69 0.9625
2024-05-07 2024-03-31 13F MERCK COM 58933Y105 2,266,146 -81,814 -3.48 299,023 16.81 1.0405
2024-02-06 2023-12-31 13F MERCK COM 58933Y105 2,347,960 -29,847 -1.26 255,984 4.57 0.9403
2023-11-02 2023-09-30 13F MERCK COM 58933Y105 2,377,807 -67,379 -2.76 244,808 -13.24 0.9767
2023-08-09 2023-06-30 13F MERCK COM 58933Y105 2,445,186 -99,267 -3.90 282,171 4.23 1.0533
2023-05-11 2023-03-31 13F MERCK COM 58933Y105 2,544,453 -23,628 -0.92 270,728 -5.01 1.0482
2023-02-13 2022-12-31 13F/A-1 MERCK COM 58933Y105 2,568,081 194,358 8.19 285,018 39.41 1.1464
2023-02-13 2022-12-31 13F MERCADOLIBRE COM 58933Y105 2,568,472 194,749 285,373 1.1479
2022-11-17 2022-09-30 13F/A-1 MERCK COM 58933Y105 2,373,723 65,418 2.83 204,447 3.42 0.9082
2022-11-14 2022-09-30 13F MERCK COM 58933Y105 2,373,723 65,418 200,724 0.1712
2022-08-05 2022-06-30 13F MERCK COM 58933Y105 2,308,305 248,399 12.06 197,687 16.96 0.9310
2022-05-09 2022-03-31 13F MERCK & CO. COM 58933Y105 2,059,906 -43,972 -2.09 169,014 4.82 0.7465
2022-02-07 2021-12-31 13F MERCK COM 58933Y105 2,103,878 11,549 0.55 161,241 2.60 0.6774
2021-10-28 2021-09-30 13F MERCK COM 58933Y105 2,092,329 -29,177 -1.38 157,154 -4.75 0.7076
2021-08-13 2021-06-30 13F MERCK COM 58933Y105 2,121,506 -79,132 -3.60 164,988 -2.75 0.7245
2021-05-06 2021-03-31 13F MERCK & CO. COM 58933Y105 2,200,638 -29,987 -1.34 169,646 -7.03 0.7321
2021-02-12 2020-12-31 13F MERCK & CO. COM 58933Y105 2,230,625 -37,073 -1.63 182,466 -3.00 0.8004
2020-11-06 2020-09-30 13F MERCK & CO. COM 58933Y105 2,267,698 -19,079 -0.83 188,104 6.37 0.9235
2020-07-29 2020-06-30 13F MERCK & CO. COM 58933Y105 2,286,777 -32,073 -1.38 176,838 -0.88 0.9478
2020-05-14 2020-03-31 13F MERCK & CO. COM 58933Y105 2,318,850 -23,780 -1.02 178,411 -16.26 1.0552
2020-02-07 2019-12-31 13F MERCK COM 58933Y105 2,342,630 -272,957 -10.44 213,063 -3.23 1.0007
2019-11-12 2019-09-30 13F MERCK COM 58933Y105 2,615,587 -35,753 -1.35 220,180 -0.96 1.0985
2019-08-12 2019-06-30 13F MERCK COM 58933Y105 2,651,340 -42,070 -1.56 222,314 -0.76 1.1612
2019-05-15 2019-03-31 13F MERCK COM 58933Y105 2,693,410 -18,434 -0.68 224,011 8.11 1.1713
2019-02-01 2018-12-31 13F MERCK COM 58933Y105 2,711,844 -88,977 -3.18 207,212 4.29 1.1895
2018-11-09 2018-09-30 13F MERCK COM 58933Y105 2,800,821 -63,186 -2.21 198,690 14.29 0.9939
2018-08-10 2018-06-30 13F MERCK COM 58933Y105 2,864,007 -37,791 -1.30 173,845 9.99 0.9357
2018-05-04 2018-03-31 13F MERCK COM 58933Y105 2,901,798 -62,287 -2.10 158,061 -5.23 0.8492
2018-02-06 2017-12-31 13F MERCK COM 58933Y105 2,964,085 107,974 3.78 166,790 -8.80 0.8741
2017-11-13 2017-09-30 13F MERCK COM 58933Y105 2,856,111 17,161 0.60 182,875 0.51 0.9921
2017-08-11 2017-06-30 13F MERCK COM 58933Y105 2,838,950 -105,958 -3.60 181,947 -2.76 1.0742
2017-05-10 2017-03-31 13F MERCK COM 58933Y105 2,944,908 -43,347 -1.45 187,119 6.37 1.1298
2017-02-14 2016-12-31 13F MERCK COM 58933Y105 2,988,255 -1,198,810 -28.63 175,918 -32.68 1.0958
2016-11-04 2016-09-30 13F MERCK COM 58933Y105 4,187,065 -181,286 -4.15 261,315 3.84 1.6650
2016-08-04 2016-06-30 13F MERCK COM 58933Y105 4,368,351 13,859 0.32 251,660 9.23 1.6936
2016-05-11 2016-03-31 13F MERCK & CO INC COM 58933Y105 4,354,492 -79,392 -1.79 230,396 -1.62 1.5595
2016-02-12 2015-12-31 13F MERCK & CO INC COM 58933Y105 4,433,884 -84,847 -1.88 234,197 4.94 1.5545
2015-11-13 2015-09-30 13F MERCK & CO INC COM 58933Y105 4,518,731 -493,345 -9.84 223,179 -21.78 1.5207
2015-08-14 2015-06-30 13F MERCK & CO INC COM 58933Y105 5,012,076 -8,436 -0.17 285,337 -1.12 1.7210
2015-05-14 2015-03-31 13F MERCK & CO INC COM 58933Y105 5,020,512 68,526 1.38 288,579 2.62 1.7998
2015-02-12 2014-12-31 13F MERCK & CO INC COM 58933Y105 4,951,986 253,360 5.39 281,223 0.96 1.7605
2014-11-14 2014-09-30 13F MERCK & CO INC COM 58933Y105 4,698,626 4,270,775 998.19 278,536 1,025.31 1.9520
2014-08-13 2014-06-30 13F MERCK COMMON 58933Y105 427,851 -22,119 -4.92 24,752 -3.10 1.0353
2014-05-14 2014-03-31 13F MERCK COMMON STOCK 58933Y105 449,970 -14,892 -3.20 25,545 9.80 1.0596
2014-02-12 2013-12-31 13F MERCK COMMON STOCK 58933Y105 464,862 -8,469 -1.79 23,266 3.25 0.9746
2013-11-13 2013-09-30 13F MERCK COMMON STOCK 58933Y105 473,331 -23,688 -4.77 22,534 -2.40 1.0752
2013-07-30 2013-06-30 13F MERCK COMMON STOCK 58933Y105 497,019 497,019 23,088 1.1195
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2025-08-13 2025-06-30 13F MERCK COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2025-04-30 2025-03-31 13F MERCK COM Call 77 -13.48 7 -14.29 n/a n/a n/a
2025-02-06 2024-12-31 13F MERCK COM Call 89 -6.32 8 n/a n/a n/a
2024-11-19 2024-09-30 13F/A MERCK COM Call 95 -37.50 0 -100.00 n/a n/a n/a
2024-11-15 2024-09-30 13F MERCK COM Call 95 0 n/a n/a n/a
2024-07-31 2024-06-30 13F MERCK COM Call 152 -11.63 5 -95.56 n/a n/a n/a
2024-05-07 2024-03-31 13F MERCK COM Call 172 25.55 90 119.51 n/a n/a n/a
2024-02-06 2023-12-31 13F MERCK COM Call 137 -15.43 41 4,000.00 n/a n/a n/a
2023-11-02 2023-09-30 13F MERCK COM Call 162 -4.71 1 -85.71 n/a n/a n/a
2023-08-09 2023-06-30 13F MERCK COM Call 170 -15.84 8 -65.00 n/a n/a n/a
2023-05-11 2023-03-31 13F MERCK COM Call 202 20 n/a n/a n/a
2023-02-13 2022-12-31 13F/A MERCK COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2023-02-13 2022-12-31 13F MERCK COM Call 0 0 n/a n/a n/a
2022-11-17 2022-09-30 13F/A MERCK COM Call 368 41.54 20 -47.37 n/a n/a n/a
2022-11-14 2022-09-30 13F MERCK COM Call 368 20 n/a n/a n/a
2022-08-05 2022-06-30 13F MERCK COM Call 260 -2.99 38 -11.63 n/a n/a n/a
2022-05-09 2022-03-31 13F MERCK & CO. COM Call 268 15.02 43 13.16 n/a n/a n/a
2022-02-07 2021-12-31 13F MERCK COM Call 233 23.94 38 31.03 n/a n/a n/a
2021-10-28 2021-09-30 13F MERCK COM Call 188 -17.18 29 70.59 n/a n/a n/a
2021-08-13 2021-06-30 13F MERCK COM Call 227 129.29 17 325.00 n/a n/a n/a
2021-05-06 2021-03-31 13F MERCK & CO. COM Call 99 4.21 4 -71.43 n/a n/a n/a
2021-02-12 2020-12-31 13F MERCK & CO. COM Call 95 39.71 14 -6.67 n/a n/a n/a
2020-11-06 2020-09-30 13F MERCK & CO. COM Call 68 9.68 15 66.67 n/a n/a n/a
2020-07-29 2020-06-30 13F MERCK & CO. COM Call 62 0.00 9 -30.77 n/a n/a n/a
2020-05-14 2020-03-31 13F MERCK & CO. COM Call 62 0.00 13 -74.00 n/a n/a n/a
2020-02-07 2019-12-31 13F MERCK COM Call 62 0.00 50 42.86 n/a n/a n/a
2019-11-12 2019-09-30 13F MERCK COM Call 62 0.00 35 -2.78 n/a n/a n/a
2019-08-12 2019-06-30 13F MERCK COM Call 62 -18.42 36 -26.53 n/a n/a n/a
2019-05-15 2019-03-31 13F MERCK COM Call 76 204.00 49 308.33 n/a n/a n/a
2019-02-01 2018-12-31 13F MERCK COM Call 25 0.00 12 140.00 n/a n/a n/a
2018-11-09 2018-09-30 13F MERCK COM Call 25 -10.71 5 150.00 n/a n/a n/a
2018-08-10 2018-06-30 13F MERCK COM Call 28 0.00 2 100.00 n/a n/a n/a
2018-05-04 2018-03-31 13F MERCK COM Call 28 0.00 1 0.00 n/a n/a n/a
2018-02-06 2017-12-31 13F MERCK COM Call 28 3.70 1 0.00 n/a n/a n/a
2017-11-13 2017-09-30 13F MERCK COM Call 27 8.00 1 -66.67 n/a n/a n/a
2017-08-11 2017-06-30 13F MERCK COM Call 25 -13.79 3 50.00 n/a n/a n/a
2017-05-10 2017-03-31 13F MERCK COM Call 29 -9.38 2 0.00 n/a n/a n/a
2017-02-14 2016-12-31 13F MERCK COM Call 32 23.08 2 -50.00 n/a n/a n/a
2016-11-04 2016-09-30 13F MERCK COM Call 26 0.00 4 300.00 n/a n/a n/a
2016-08-04 2016-06-30 13F MERCK COM Call 26 -96.75 1 n/a n/a n/a
2016-05-11 2016-03-31 13F MERCK & CO INC COM Call 800 -57.89 0 -100.00 n/a n/a n/a
2016-02-12 2015-12-31 13F MERCK & CO INC COM Call 1,900 -26.92 1 n/a n/a n/a
2015-11-13 2015-09-30 13F MERCK & CO INC COM Call 2,600 -18.75 0 n/a n/a n/a
2015-08-14 2015-06-30 13F MERCK & CO INC COM Call 3,200 14.29 0 -100.00 n/a n/a n/a
2015-05-14 2015-03-31 13F MERCK & CO INC COM Call 2,800 -47.17 1 0.00 n/a n/a n/a
2015-02-12 2014-12-31 13F MERCK & CO INC COM Call 5,300 6.00 1 -83.33 n/a n/a n/a
2014-11-14 2014-09-30 13F MERCK & CO INC COM Call 5,000 6 n/a n/a n/a
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.