머크 앤 컴퍼니(Merck & Co., Inc.)
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionHaverford Trust Co
Latest Disclosed Ownership277,400 shares
Latest Disclosed Value $ 33,368,408
Haverford Trust Co reports 0.80% decrease in ownership of MRK / Merck & Co., Inc.

On May 11, 2026 - Haverford Trust Co filed a 13F-HR form disclosing ownership of 277,400 shares of Merck & Co., Inc. (MX:MRK) valued at $33,368,408 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 279,635 shares of Merck & Co., Inc.. This represents a change in shares of -0.80% 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)
2026-05-11 2026-03-31 13F MERCK COM 58933Y105 277,400 -2,235 -0.80 33,368 13.37 0.3058
2026-02-13 2025-12-31 13F MERCK COM 58933Y105 279,635 -10,004 -3.45 29,434 21.08 0.2625
2025-11-14 2025-09-30 13F MERCK COM 58933Y105 289,639 -19,617 -6.34 24,309 -0.70 0.2193
2025-08-13 2025-06-30 13F MERCK COM 58933Y105 309,256 -244,933 -44.20 24,481 -50.79 0.2326
2025-05-14 2025-03-31 13F MERCK COM 58933Y105 554,189 -174,880 -23.99 49,744 -31.41 0.5007
2025-02-11 2024-12-31 13F MERCK COM 58933Y105 729,069 -26,143 -3.46 72,528 -15.43 0.7201
2024-11-05 2024-09-30 13F MERCK COM 58933Y105 755,212 -54,165 -6.69 85,762 -14.41 0.8356
2024-08-13 2024-06-30 13F MERCK COM 58933Y105 809,377 -12,073 -1.47 100,201 -7.56 1.0547
2024-05-02 2024-03-31 13F MERCK COM 58933Y105 821,450 7,191 0.88 108,390 22.10 1.1325
2024-02-08 2023-12-31 13F MERCK COM 58933Y105 814,259 5,860 0.72 88,770 6.66 0.9848
2023-11-09 2023-09-30 13F MERCK COM 58933Y105 808,399 -26,565 -3.18 83,225 -13.62 1.0142
2023-08-08 2023-06-30 13F MERCK COM 58933Y105 834,964 -7,118 -0.85 96,347 7.54 1.0872
2023-05-12 2023-03-31 13F MERCK COM 58933Y105 842,082 -138,489 -14.12 89,589 -17.65 1.0700
2023-02-13 2022-12-31 13F MERCK COM 58933Y105 980,571 -3,851 -0.39 108,794 28.33 1.3396
2022-11-14 2022-09-30 13F MERCK COM 58933Y105 984,422 17,143 1.77 84,778 -3.87 1.1614
2022-08-12 2022-06-30 13F MERCK COM 58933Y105 967,279 3,827 0.40 88,187 11.56 1.1494
2022-05-05 2022-03-31 13F MERCK COM 58933Y105 963,452 59,841 6.62 79,051 14.15 0.9131
2022-02-14 2021-12-31 13F MERCK COM 58933Y105 903,611 28,248 3.23 69,253 5.33 0.7545
2021-11-12 2021-09-30 13F MERCK COM 58933Y105 875,363 29,146 3.44 65,749 -0.09 0.7863
2021-08-16 2021-06-30 13F/A-1 MERCK COM 58933Y105 846,217 43,519 5.42 65,810 6.35 0.7745
2021-08-16 2021-06-30 13F MERCK COM 58933Y105 65,810 -736,888 65,810 0.7745
2021-05-12 2021-03-31 13F MERCK COM 58933Y105 802,698 115,181 16.75 61,880 10.03 0.7919
2021-02-05 2020-12-31 13F MERCK COM 58933Y105 687,517 20,933 3.14 56,239 1.71 0.7944
2020-11-10 2020-09-30 13F MERCK COM 58933Y105 666,584 50,242 8.15 55,293 16.01 0.8817
2020-08-13 2020-06-30 13F MERCK COM 58933Y105 616,342 41,999 7.31 47,662 7.86 0.8175
2020-05-11 2020-03-31 13F MERCK COM 58933Y105 574,343 38,495 7.18 44,190 -9.33 0.8975
2020-02-10 2019-12-31 13F MERCK COM 58933Y105 535,848 -1,004 -0.19 48,735 7.84 0.7895
2019-11-04 2019-09-30 13F MERCK COM 58933Y105 536,852 8,045 1.52 45,192 1.92 0.7931
2019-08-13 2019-06-30 13F MERCK COM 58933Y105 528,807 4,923 0.94 44,340 1.76 0.7954
2019-05-09 2019-03-31 13F MERCK COM 58933Y105 523,884 9,457 1.84 43,571 10.85 0.8088
2019-02-12 2018-12-31 13F MERCK COM 58933Y105 514,427 -7,135 -1.37 39,307 6.24 0.8368
2018-11-08 2018-09-30 13F MERCK COM 58933Y105 521,562 -5,625 -1.07 37,000 15.63 0.6831
2018-08-10 2018-06-30 13F MERCK COM 58933Y105 527,187 -8,139 -1.52 32,000 9.74 0.6322
2018-05-09 2018-03-31 13F MERCK COM 58933Y105 535,326 -181,221 -25.29 29,159 -27.68 0.5837
2018-02-13 2017-12-31 13F MERCK COM 58933Y105 716,547 3,542 0.50 40,320 -11.68 0.7915
2017-11-09 2017-09-30 13F MERCK COM 58933Y105 713,005 8,509 1.21 45,654 1.11 0.9534
2017-08-14 2017-06-30 13F MERCK COM 58933Y105 704,496 13,367 1.93 45,151 2.82 0.9851
2017-05-05 2017-03-31 13F MERCK COM 58933Y105 691,129 9,020 1.32 43,914 9.36 1.0025
2017-02-10 2016-12-31 13F MERCK COM 58933Y105 682,109 14,250 2.13 40,156 -3.66 0.9730
2016-11-14 2016-09-30 13F MERCK COM 58933Y105 667,859 6,578 0.99 41,681 9.41 1.0393
2016-08-04 2016-06-30 13F MERCK COM 58933Y105 661,281 11,334 1.74 38,096 10.78 0.9567
2016-05-10 2016-03-31 13F MERCK COM 58933Y105 649,947 31,192 5.04 34,389 5.22 0.8951
2016-02-09 2015-12-31 13F MERCK COM 58933Y105 618,755 30,840 5.25 32,683 12.56 0.8795
2015-11-10 2015-09-30 13F MERCK COM 58933Y105 587,915 21,627 3.82 29,037 -9.93 0.8434
2015-07-30 2015-06-30 13F MERCK COM 58933Y105 566,288 4,228 0.75 32,239 -0.21 0.8858
2015-05-05 2015-03-31 13F/A-1 MERCK COM 58933Y105 562,060 4,176 0.75 32,307 1.97 0.8936
2015-05-04 2015-03-31 13F MERCK COM 58933Y105 45,649 32,307
2015-02-09 2014-12-31 13F MERCK COM 58933Y105 557,884 1,026 0.18 31,682 -4.03 0.8878
2014-11-05 2014-09-30 13F MERCK COM 58933Y105 556,858 6,472 1.18 33,011 3.68 0.9861
2014-08-01 2014-06-30 13F MERCK COM 58933Y105 550,386 13,592 2.53 31,840 4.48 0.9343
2014-05-08 2014-03-31 13F MERCK COM 58933Y105 536,794 -84,745 -13.63 30,474 -2.04 0.9417
2014-01-31 2013-12-31 13F MERCK Common Stocks 58933Y105 621,539 15,315 2.53 31,108 7.78 0.8736
2013-11-01 2013-09-30 13F MERCK Common Stocks 58933Y105 606,224 25,134 4.33 28,862 6.93 1.0500
2013-07-31 2013-06-30 13F MERCK Common Stocks 58933Y105 581,090 581,090 26,992 0.8887
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.