Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionFirst Dallas Securities Inc.
Latest Disclosed Ownership10,730 shares
Latest Disclosed Value $ 1,290,701
First Dallas Securities Inc. reports 0.55% increase in ownership of MRK / Merck & Co., Inc.

On April 27, 2026 - First Dallas Securities Inc. filed a 13F-HR form disclosing ownership of 10,730 shares of Merck & Co., Inc. (MX:MRK) valued at $1,290,701 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 11, 2026 disclosing 10,671 shares of Merck & Co., Inc.. This represents a change in shares of 0.55% 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)
2026-04-27 2026-03-31 13F Merck COM 58933Y105 10,730 59 0.55 1,291 14.87 0.4775
2026-02-11 2025-12-31 13F Merck COM 58933Y105 10,671 162 1.54 1,123 27.32 0.4179
2026-02-11 2025-12-31 13F Merck COM 58933Y105 10,671 1,123
2025-11-05 2025-09-30 13F Merck COM 58933Y105 10,509 -1,418 -11.89 882 -6.57 0.3304
2025-08-07 2025-06-30 13F Merck COM 58933Y105 11,927 -8,737 -42.28 944 -49.11 0.3732
2025-05-16 2025-03-31 13F MERCK COM 58933Y105 20,664 -672 -3.15 1,855 -12.58 0.7751
2025-01-24 2024-12-31 13F MERCK COM 58933Y105 21,336 -3,895 -15.44 2,122 -25.93 0.8648
2024-11-18 2024-09-30 13F MERCK COM 58933Y105 25,231 2,904 13.01 2,865 3.65 1.1975
2024-08-02 2024-06-30 13F MERCK COM 58933Y105 22,327 1,768 8.60 2,764 138,100.00 1.2132
2024-04-16 2024-03-31 13F MERCK COM 58933Y105 20,559 2,009 10.83 3 0.00 1.2480
2024-02-13 2023-12-31 13F MERCK COM 58933Y105 18,550 5,896 46.59 2 100.00 1.0418
2023-11-14 2023-09-30 13F MERCK COM 58933Y105 12,654 -3,656 -22.42 1 0.00 0.2984
2023-08-07 2023-06-30 13F MERCK COM 58933Y105 16,310 661 4.22 2 0.00 1.0499
2023-05-15 2023-03-31 13F MERCK COM 58933Y105 15,649 9 0.06 2 0.00 0.9822
2023-02-03 2022-12-31 13F MERCK COM 58933Y105 15,640 7,213 85.59 2 -99.86 1.0458
2022-10-21 2022-09-30 13F MERCK COM 58933Y105 8,427 2,136 33.95 726 26.48 0.4988
2022-07-28 2022-06-30 13F MERCK & CO. COM 58933Y105 6,291 12 0.19 574 11.46 0.3868
2022-05-12 2022-03-31 13F MERCK COM 58933Y105 6,279 350 5.90 515 13.44 0.2909
2022-02-07 2021-12-31 13F MERCK COM 58933Y105 5,929 -147 -2.42 454 -0.44 0.2978
2021-10-06 2021-09-30 13F MERCK COM 58933Y105 6,076 -11,321 -65.07 456 -66.30 0.3147
2021-07-06 2021-06-30 13F MERCK & CO. COM 58933Y105 17,397 -3,096 -15.11 1,353 -14.37 0.8867
2021-05-26 2021-03-31 13F MERCK & CO. COM 58933Y105 20,493 -4,896 -19.28 1,580 -23.93 1.3439
2021-02-01 2020-12-31 13F MERCK & CO. COM 58933Y105 25,389 -996 -3.77 2,077 -5.12 1.8754
2020-10-15 2020-09-30 13F MERCK & CO. COM 58933Y105 26,385 -10,437 -28.34 2,189 -22.73 2.4610
2020-05-04 2020-03-31 13F MERCK COM 58933Y105 36,822 -445 -1.19 2,833 -16.41 3.9490
2020-02-04 2019-12-31 13F MERCK COM 58933Y105 37,267 5 0.01 3,389 8.03 2.8926
2019-11-14 2019-09-30 13F MERCK COM 58933Y105 37,262 550 1.50 3,137 1.92 2.7814
2019-08-22 2019-06-30 13F MERCK COM 58933Y105 36,712 6,732 22.45 3,078 23.47 2.6923
2019-05-17 2019-03-31 13F Merck COM 58933Y105 29,980 21,944 273.07 2,493 306.03 1.7929
2019-02-11 2018-12-31 13F Merck COM 58933Y105 8,036 -150 -1.83 614 5.68 0.5117
2018-10-31 2018-09-30 13F Merck COM 58933Y105 8,186 1 0.01 581 16.90 0.3630
2018-07-31 2018-06-30 13F Merck COM 58933Y105 8,185 -425 -4.94 497 8.28 0.3178
2018-05-04 2018-03-31 13F Merck COM 58933Y105 8,610 -2,922 -25.34 459 -29.28 0.2997
2018-02-07 2017-12-31 13F MERCK & CO INC COM 58933Y105 11,532 -250 -2.12 649 -14.04 0.4127
2017-11-07 2017-09-30 13F Merck & Co Inc COM 58933Y105 11,782 322 2.81 755 2.86 0.5233
2017-08-14 2017-06-30 13F Merck COM 58933Y105 11,460 -1,220 -9.62 734 -8.82 0.5362
2017-05-05 2017-03-31 13F Merck COM 58933Y105 12,680 -349 -2.68 805 4.95 0.5613
2017-01-11 2016-12-31 13F MERCK COM 58933Y105 13,029 -449 -3.33 767 -8.80 0.5248
2016-11-15 2016-09-30 13F MERCK COM 58933Y105 13,478 -299 -2.17 841 6.05 0.6240
2016-07-26 2016-06-30 13F MERCK COM 58933Y105 13,777 301 2.23 793 11.22 0.6122
2016-05-03 2016-03-31 13F MERCK COM 58933Y105 13,476 -249 -1.81 713 -1.66 0.5768
2016-01-27 2015-12-31 13F MERCK COM 58933Y105 13,725 -149 -1.07 725 5.84 0.5938
2015-11-12 2015-09-30 13F MERCK COM 58933Y105 13,874 -149 -1.06 685 -14.27 0.5631
2015-07-27 2015-06-30 13F Merck COM 58933Y105 14,023 -299 -2.09 799 -3.03 0.5762
2015-05-05 2015-03-31 13F/A-1 Merck COM 58933Y105 14,322 -2,434 -14.53 824 -13.35 0.5746
2015-05-05 2015-03-31 13F Merck COM 58933Y105 14,322 824
2015-02-17 2014-12-31 13F Merck COM 58933Y105 16,756 588 3.64 951 -0.73 0.6188
2014-11-12 2014-09-30 13F Merck COM 58933Y105 16,168 -1,799 -10.01 958 -7.80 0.5690
2014-07-11 2014-06-30 13F MERCK & CO INC NEW COM COM 58933Y105 17,967 -199 -1.10 1,039 0.78 0.6244
2014-04-15 2014-03-31 13F MERCK & CO INC NEW COM COM 58933Y105 18,166 -399 -2.15 1,031 10.98 0.6885
2014-01-29 2013-12-31 13F MERCK & CO INC NEW COM COM 58933Y105 18,565 -689 -3.58 929 1.42 0.6226
2013-11-13 2013-09-30 13F/A-1 MERCK & CO INC NEW COM COM 58933Y105 19,254 -695 -3.48 916 -1.08 0.6994
2013-11-12 2013-09-30 13F MERCK & CO INC NEW COM COM 58933Y105 19,254 916
2013-08-15 2013-06-30 13F MERCK & CO INC COM 58933Y105 19,949 19,949 926 0.7132
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.