Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionWelch Group, LLC
Latest Disclosed Ownership36,783 shares
Latest Disclosed Value $ 4,424,622
Welch Group, LLC reports 6.68% increase in ownership of MRK / Merck & Co., Inc.

On April 21, 2026 - Welch Group, LLC filed a 13F-HR form disclosing ownership of 36,783 shares of Merck & Co., Inc. (MX:MRK) valued at $4,424,622 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 26, 2026 disclosing 34,481 shares of Merck & Co., Inc.. This represents a change in shares of 6.68% 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)
2026-04-21 2026-03-31 13F MERCK COMMON 58933Y105 36,783 2,302 6.68 4,425 21.91 0.1662
2026-01-26 2025-12-31 13F MERCK COMMON STOCK 58933Y105 34,481 239 0.70 3,630 26.31 0.1399
2025-10-14 2025-09-30 13F MERCK COMMON 58933Y105 34,242 956 2.87 2,874 9.07 0.1122
2025-07-25 2025-06-30 13F MERCK COMMON 58933Y105 33,286 1,419 4.45 2,635 -7.35 0.1101
2025-04-08 2025-03-31 13F MERCK COMMON 58933Y105 31,867 1,204 3.93 2,844 -5.74 0.1251
2025-01-27 2024-12-31 13F MERCK COMMON 58933Y105 30,663 -37 -0.12 3,016 -13.48 0.1358
2024-10-24 2024-09-30 13F MERCK COMMON 58933Y105 30,700 46 0.15 3,486 -8.12 0.1516
2024-07-17 2024-06-30 13F MERCK COMMON 58933Y105 30,654 -196 -0.64 3,795 -6.78 0.1823
2024-04-09 2024-03-31 13F MERCK COMMON 58933Y105 30,850 1,040 3.49 4,071 25.27 0.2019
2024-01-23 2023-12-31 13F MERCK Common 58933Y105 29,810 -270 -0.90 3,250 4.94 0.1750
2023-10-18 2023-09-30 13F MERCK Common 58933Y105 30,080 35 0.12 3,097 -10.68 0.1835
2023-07-18 2023-06-30 13F MERCK Common 58933Y105 30,045 255 0.86 3,467 9.37 0.1987
2023-04-13 2023-03-31 13F MERCK Common 58933Y105 29,790 5 0.02 3,169 -4.09 0.1842
2023-01-30 2022-12-31 13F MERCK Common 58933Y105 29,785 259 0.88 3,305 29.93 0.1890
2022-10-13 2022-09-30 13F MERCK COMMON 58933Y105 29,526 499 1.72 2,543 -3.89 0.1655
2022-07-21 2022-06-30 13F MERCK COMMON 58933Y105 29,027 31 0.11 2,646 11.22 0.1615
2022-04-29 2022-03-31 13F MERCK COMMON 58933Y105 28,996 567 1.99 2,379 9.18 0.1358
2022-01-26 2021-12-31 13F MERCK COMMON 58933Y105 28,429 90 0.32 2,179 2.35 0.1275
2021-11-05 2021-09-30 13F MERCK COMMON 58933Y105 28,339 270 0.96 2,129 -2.47 0.1441
2021-07-21 2021-06-30 13F MERCK COMMON 58933Y105 28,069 101 0.36 2,183 1.25 0.1488
2021-04-23 2021-03-31 13F MERCK & CO. COMMON 58933Y105 27,968 1,532 5.80 2,156 -0.28 0.1552
2021-01-25 2020-12-31 13F MERCK & CO. Common 58933Y105 26,436 -94 -0.35 2,162 -1.77 0.1734
2020-10-28 2020-09-30 13F MERCK & CO. Common 58933Y105 26,530 -1,505 -5.37 2,201 1.52 0.1923
2020-07-22 2020-06-30 13F MERCK & CO. Common 58933Y105 28,035 7,210 34.62 2,168 35.33 0.2025
2020-04-28 2020-03-31 13F MERCK & CO. Common 58933Y105 20,825 9,304 80.76 1,602 52.86 0.1709
2020-01-24 2019-12-31 13F Merck Common 589331107 11,521 1,172 11.32 1,048 20.32 0.1031
2019-11-05 2019-09-30 13F Merck Common 589331107 10,349 -115 -1.10 871 -0.68 0.0895
2019-07-11 2019-06-30 13F Merck Common 589331107 10,464 219 2.14 877 2.93 0.0936
2019-04-15 2019-03-31 13F Merck Common 589331107 10,245 518 5.33 852 14.67 0.0938
2019-01-10 2018-12-31 13F Merck Common 589331107 9,727 103 1.07 743 8.78 0.0910
2018-11-01 2018-09-30 13F Merck Common 589331107 9,624 53 0.55 683 17.56 0.0711
2018-07-30 2018-06-30 13F Merck Common 589331107 9,571 2,231 30.40 581 45.25 0.0724
2018-04-23 2018-03-31 13F Merck Common 589331107 7,340 740 11.21 400 7.82 0.0506
2018-02-01 2017-12-31 13F Merck Common 589331107 6,600 521 8.57 371 -4.63 0.0576
2017-11-07 2017-09-30 13F Merck Common 589331107 6,079 0 0.00 389 -0.26 0.0650
2017-08-07 2017-06-30 13F Merck Common 589331107 6,079 -1,118 -15.53 390 -14.85 0.0650
2017-05-01 2017-03-31 13F Merck Common 589331107 7,197 -635 -8.11 458 -0.65 0.0862
2017-02-09 2016-12-31 13F Merck Common 589331107 7,832 -152 -1.90 461 -7.43 0.0901
2016-10-28 2016-09-30 13F Merck Common 589331107 7,984 832 11.63 498 20.87 0.0990
2016-07-27 2016-06-30 13F Merck Common 589331107 7,152 -10,782 -60.12 412 -56.59 0.0839
2016-05-05 2016-03-31 13F Merck Common 589331107 17,934 -187 -1.03 949 -0.84 0.1585
2016-01-21 2015-12-31 13F Merck Common 589331107 18,121 533 3.03 957 10.13 0.1718
2015-10-23 2015-09-30 13F Merck COM 589331107 17,588 500 2.93 869 -10.69 0.1680
2015-07-31 2015-06-30 13F Merck Common 589331107 17,088 -1,040 -5.74 973 -6.62 0.1842
2015-04-29 2015-03-31 13F Merck Common 589331107 18,128 0 0.00 1,042 1.26 0.1913
2015-01-20 2014-12-31 13F Merck Common 589331107 18,128 0 0.00 1,029 -4.28 0.1985
2014-10-29 2014-09-30 13F Merck Common 589331107 18,128 0 0.00 1,075 2.48 0.2222
2014-07-22 2014-06-30 13F Merck Common 589331107 18,128 -163 -0.89 1,049 1.06 0.2172
2014-04-23 2014-03-31 13F Merck COM 589331107 18,291 -5,546 -23.27 1,038 -12.99 0.2351
2014-02-07 2013-12-31 13F Merck Common 589331107 23,837 864 3.76 1,193 9.05 0.2705
2013-10-04 2013-09-30 13F Merck Common 589331107 22,973 -342 -1.47 1,094 1.02 0.2689
2013-07-29 2013-06-30 13F Merck Common 589331107 23,315 23,315 1,083 0.2811
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.