Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionSumitomo Life Insurance Co
Latest Disclosed Ownership24,295 shares
Latest Disclosed Value $ 2,922,446
Sumitomo Life Insurance Co reports 2.58% increase in ownership of MRK / Merck & Co., Inc.

On May 12, 2026 - Sumitomo Life Insurance Co filed a 13F-HR form disclosing ownership of 24,295 shares of Merck & Co., Inc. (MX:MRK) valued at $2,922,446 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 23,683 shares of Merck & Co., Inc.. This represents a change in shares of 2.58% 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)
2026-05-12 2026-03-31 13F MERCK & CO INC COM Common 58933Y105 24,295 612 2.58 2,922 17.26 0.0687
2026-02-13 2025-12-31 13F MERCK & CO INC COM Common 58933Y105 23,683 153 0.65 2,493 26.24 0.0683
2025-11-12 2025-09-30 13F MERCK & CO INC COM Common 58933Y105 23,530 -707 -2.92 1,975 2.92 0.0613
2025-08-05 2025-06-30 13F MERCK & CO INC COM Common 58933Y105 24,237 -1,509 -5.86 1,919 -16.97 0.1301
2025-05-02 2025-03-31 13F MERCK & CO INC COM Common 58933Y105 25,746 -392 -1.50 2,311 -11.15 0.0827
2025-01-23 2024-12-31 13F MERCK & CO INC COM Common 58933Y105 26,138 -63,656 -70.89 2,600 -74.50 0.0491
2024-10-16 2024-09-30 13F MERCK & CO INC COM Common 58933Y105 89,794 14,744 19.65 10,197 7.85 0.2002
2024-07-19 2024-06-30 13F MERCK & CO INC COM Common 58933Y105 75,050 45,595 154.80 9,456 143.31 0.2188
2024-04-26 2024-03-31 13F MERCK & CO INC COM Common 58933Y105 29,455 -1,121 -3.67 3,887 16.59 0.1009
2024-01-30 2023-12-31 13F MERCK & CO INC COM Common 58933Y105 30,576 -1,588 -4.94 3,333 0.66 0.1036
2023-10-23 2023-09-30 13F MERCK & CO INC COM Common 58933Y105 32,164 -423 -1.30 3,311 -11.94 0.0932
2023-07-20 2023-06-30 13F MERCK & CO INC COM Common 58933Y105 32,587 -3,160 -8.84 3,760 125,233.33 0.1654
2023-04-27 2023-03-31 13F MERCK & CO INC COM Common 58933Y105 35,747 -8,510 -19.23 4 -25.00 0.3200
2023-01-18 2022-12-31 13F MERCK & CO INC COM Common 58933Y105 44,257 -420 -0.94 5 -99.90 0.3620
2022-10-31 2022-09-30 13F MERCK & CO INC COM Common 58933Y105 44,677 -5,440 -10.85 3,848 -15.78 0.1631
2022-07-22 2022-06-30 13F MERCK & CO INC COM Common 58933Y105 50,117 988 2.01 4,569 13.35 0.1279
2022-04-27 2022-03-31 13F MERCK & CO INC COM Common 58933Y105 49,129 -732 -1.47 4,031 5.50 0.0997
2022-02-04 2021-12-31 13F MERCK & CO INC COM Common 58933Y105 49,861 -1,606 -3.12 3,821 -1.16 0.0909
2021-10-25 2021-09-30 13F MERCK & CO INC COM Common 58933Y105 51,467 -3,243 -5.93 3,866 -9.14 0.1034
2021-07-20 2021-06-30 13F MERCK & CO. INC COM Common 58933Y105 54,710 -7,056 -11.42 4,255 -10.65 0.1353
2021-04-27 2021-03-31 13F MERCK & CO. INC COM Common 58933Y105 61,766 -3,977 -6.05 4,762 -11.45 0.1916
2021-02-05 2020-12-31 13F MERCK & CO. INC COM Common 58933Y105 65,743 -4,225 -6.04 5,378 -7.34 0.2272
2020-10-29 2020-09-30 13F MERCK & CO. INC COM Common 58933Y105 69,968 -5,855 -7.72 5,804 -1.01 0.2700
2020-07-22 2020-06-30 13F MERCK & CO. INC COM Common 58933Y105 75,823 -6,601 -8.01 5,863 -7.55 0.3143
2020-05-01 2020-03-31 13F MERCK & CO. INC COM Common 58933Y105 82,424 1,360 1.68 6,342 -13.98 0.4513
2020-01-24 2019-12-31 13F MERCK & CO INC NEW COM Common 58933Y105 81,064 4,566 5.97 7,373 14.49 0.8354
2019-10-24 2019-09-30 13F MERCK & CO INC NEW COM Common 58933Y105 76,498 -9,774 -11.33 6,440 -10.98 0.8378
2019-07-26 2019-06-30 13F MERCK & CO INC NEW COM Common 58933Y105 86,272 3,479 4.20 7,234 5.05 0.8538
2019-04-17 2019-03-31 13F MERCK & CO INC NEW COM Common 58933Y105 82,793 -9,363 -10.16 6,886 -2.22 0.9256
2019-01-24 2018-12-31 13F MERCK & CO INC NEW COM Common 58933Y105 92,156 656 0.72 7,042 26.79 0.9760
2018-07-23 2018-06-30 13F MERCK & CO INC NEW COM Common 58933Y105 91,500 3,693 4.21 5,554 16.12 0.6812
2018-04-27 2018-03-31 13F MERCK & CO INC NEW COM Common 58933Y105 87,807 -3,869 -4.22 4,783 -7.29 0.6323
2018-02-01 2017-12-31 13F MERCK & CO INC NEW COM Common 58933Y105 91,676 -4,453 -4.63 5,159 -16.18 0.6473
2017-10-17 2017-09-30 13F MERCK & CO INC NEW COM Common 58933Y105 96,129 -1,748 -1.79 6,155 -1.88 0.7840
2017-07-27 2017-06-30 13F MERCK & CO INC NEW COM Common 58933Y105 97,877 -14,006 -12.52 6,273 -11.76 0.8182
2017-04-26 2017-03-31 13F MERCK & CO INC NEW COM Common 58933Y105 111,883 -1,944 -1.71 7,109 6.09 1.0049
2017-01-27 2016-12-31 13F MERCK & CO INC NEW COM Common 58933Y105 113,827 15,601 15.88 6,701 9.31 0.9555
2016-10-25 2016-09-30 13F MERCK & CO INC NEW COM Common 58933Y105 98,226 -4,475 -4.36 6,130 3.60 0.9096
2016-07-15 2016-06-30 13F MERCK & CO INC NEW COM Common 58933Y105 102,701 -3,615 -3.40 5,917 5.19 0.8108
2016-04-26 2016-03-31 13F MERCK & CO INC NEW COM Common 58933Y105 106,316 -15,819 -12.95 5,625 -12.80 0.7316
2016-01-21 2015-12-31 13F MERCK & CO INC NEW COM Common 58933Y105 122,135 8,829 7.79 6,451 15.28 0.8142
2015-10-22 2015-09-30 13F MERCK & CO INC NEW COM Common 58933Y105 113,306 -2,886 -2.48 5,596 -15.40 0.7425
2015-07-29 2015-06-30 13F MERCK & CO INC NEW COM Common 58933Y105 116,192 -28,557 -19.73 6,615 -20.49 0.8060
2015-04-30 2015-03-31 13F MERCK & CO INC NEW COM Common 58933Y105 144,749 144,749 0.00 8,320 0.9177
2015-02-04 2014-12-31 13F MERCK & CO INC NEW COM Common 58933Y105 0 -158,545 -100.00 0 -100.00
2014-11-04 2014-09-30 13F MERCK & CO INC NEW COM Common 58933Y105 158,545 -4,234 -2.60 9,399 -0.19 0.9190
2014-07-30 2014-06-30 13F MERCK & CO INC NEW COM Common 58933Y105 162,779 -7,963 -4.66 9,417 -2.85 0.9003
2014-05-02 2014-03-31 13F MERCK & CO INC NEW COM Common 58933Y105 170,742 -14,418 -7.79 9,693 4.60 0.9410
2014-02-07 2013-12-31 13F MERCK & CO INC NEW COM Common 58933Y105 185,160 -22,119 -10.67 9,267 -6.10 0.8341
2013-11-13 2013-09-30 13F MERCK & CO INC NEW COM Common 58933Y105 207,279 -19,133 -8.45 9,869 -6.16 0.9199
2013-08-08 2013-06-30 13F MERCK & CO INC NEW COM Common 058933Y10 226,412 226,412 10,517 1.0070
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.