Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionBRYN MAWR TRUST Co
Latest Disclosed Ownership226,576 shares
Latest Disclosed Value $ 27,254,827
BRYN MAWR TRUST Co reports 4.27% decrease in ownership of MRK / Merck & Co., Inc.

On April 30, 2026 - BRYN MAWR TRUST Co filed a 13F-HR form disclosing ownership of 226,576 shares of Merck & Co., Inc. (MX:MRK) valued at $27,254,827 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 12, 2026 disclosing 236,691 shares of Merck & Co., Inc.. This represents a change in shares of -4.27% 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)
2026-04-30 2026-03-31 13F MERCK COM 58933Y105 226,576 -10,115 -4.27 27,255 9.39 0.4841
2026-02-12 2025-12-31 13F MERCK COM 58933Y105 236,691 -3,282 -1.37 24,914 23.70 0.5846
2025-11-20 2025-09-30 13F/A-1 MERCK COM 58933Y105 239,973 -40,319 -14.38 20,141 -9.23 0.4855
2025-10-28 2025-09-30 13F MERCK COM 58933Y105 269,323 -10,969 22,604 0.2504
2025-07-28 2025-06-30 13F MERCK COM 58933Y105 280,292 -13,849 -4.71 22,188 -15.96 0.3948
2025-05-08 2025-03-31 13F MERCK COM 58933Y105 294,141 -8,277 -2.74 26,402 -12.24 0.4933
2025-01-28 2024-12-31 13F Merck COM 58933Y105 302,418 -11,535 -3.67 30,085 -15.62 0.5415
2024-11-25 2024-09-30 13F Merck COM 58933Y105 313,953 174,419 125.00 35,653 106.39 0.6400
2024-08-08 2024-06-30 13F MERCK & CO INC COMMON STOCK 58933Y105 139,534 -1,305 -0.93 17,274 -7.04 0.6624
2024-05-15 2024-03-31 13F MERCK & CO INC COMMON STOCK 58933Y105 140,839 -6,281 -4.27 18,584 22.70 0.7130
2023-11-15 2023-09-30 13F MERCK & CO INC COMMON STOCK 58933Y105 147,120 -921 -0.62 15,146 88,988.24 0.6666
2023-08-11 2023-06-30 13F MERCK & CO INC COMMON STOCK 58933Y105 148,041 -2,416 -1.61 17 6.25 0.7119
2023-05-15 2023-03-31 13F MERCK & CO INC COMMON STOCK 58933Y105 150,457 -3,482 -2.26 16 -5.88 0.7074
2023-02-13 2022-12-31 13F MERCK & CO INC COMMON STOCK 58933Y105 153,939 -1,570 -1.01 17 -99.87 0.7757
2022-11-14 2022-09-30 13F MERCK & CO INC COMMON STOCK 58933Y105 155,509 -306 -0.20 13,392 -5.73 0.6540
2022-08-11 2022-06-30 13F MERCK & CO INC COMMON STOCK 58933Y105 155,815 -18,075 -10.39 14,206 -0.43 0.6536
2022-05-16 2022-03-31 13F MERCK & CO INC COMMON STOCK 58933Y105 173,890 -15,584 -8.22 14,267 -1.75 0.5571
2022-02-10 2021-12-31 13F MERCK & CO INC COMMON STOCK 58933Y105 189,474 -6,690 -3.41 14,521 -1.45 0.5222
2021-10-26 2021-09-30 13F MERCK & CO INC COMMON STOCK 58933Y105 196,164 -2,217 -1.12 14,734 -4.50 0.5690
2021-07-29 2021-06-30 13F MERCK & CO INC COMMON STOCK 58933Y105 198,381 -1,955 -0.98 15,428 -0.10 0.5886
2021-04-23 2021-03-31 13F MERCK & CO INC COMMON STOCK 58933Y105 200,336 -5,873 -2.85 15,444 -8.44 0.6168
2021-02-11 2020-12-31 13F MERCK & CO INC COMMON STOCK 58933Y105 206,209 -18,771 -8.34 16,868 -9.62 0.7088
2020-11-12 2020-09-30 13F MERCK & CO INC COMMON STOCK 58933Y105 224,980 10,395 4.84 18,663 12.47 0.8650
2020-08-13 2020-06-30 13F MERCK & CO INC COMMON STOCK 58933Y105 214,585 -2,288 -1.05 16,594 -0.55 0.8159
2020-05-08 2020-03-31 13F MERCK & CO INC COMMON STOCK 58933Y105 216,873 34,595 18.98 16,685 0.64 0.9808
2020-02-11 2019-12-31 13F MERCK & CO INC COMMON STOCK 58933Y105 182,278 -6,184 -3.28 16,579 4.51 0.8409
2019-10-24 2019-09-30 13F MERCK & CO INC COMMON STOCK 58933Y105 188,462 -2,779 -1.45 15,864 -1.07 0.8657
2019-08-15 2019-06-30 13F MERCK & CO INC COMMON STOCK 58933Y105 191,241 2,900 1.54 16,035 2.36 0.8677
2019-05-15 2019-03-31 13F MERCK & CO INC COMMON STOCK 58933Y105 188,341 52 0.03 15,665 8.88 0.8531
2019-08-28 2018-12-31 13F/A-1 MERCK & CO INC COMMON STOCK 58933Y105 188,289 -28 -0.01 14,387 7.70 0.8733
2019-02-15 2018-12-31 13F MERCK & CO INC COMMON STOCK 58933Y105 186,489 -28 14,249
2019-08-28 2018-09-30 13F/A-1 MERCK & CO INC COMMON STOCK 58933Y105 188,317 1,265 0.68 13,358 17.65 0.7032
2018-11-15 2018-09-30 13F MERCK & CO INC COMMON STOCK 58933Y105 186,517 -535 13,231 0.6984
2019-08-27 2018-06-30 13F/A-1 MERCK & CO INC COMMON STOCK 58933Y105 187,052 1,608 0.87 11,354 12.39 0.6332
2018-08-14 2018-06-30 13F MERCK & CO INC COMMON STOCK 58933Y105 185,252 1,608 11,245
2019-08-27 2018-03-31 13F/A-1 MERCK & CO INC COMMON STOCK 58933Y105 185,444 -1,721 -0.92 10,102 -4.07 0.5779
2018-05-15 2018-03-31 13F MERCK & CO INC COMMON STOCK 58933Y105 183,644 -1,780 10,004
2019-08-27 2017-12-31 13F/A-1 MERCK & CO INC COMMON STOCK 58933Y105 187,165 -3,311 -1.74 10,531 -13.65 0.5749
2018-02-15 2017-12-31 13F MERCK & CO INC COMMON STOCK 58933Y105 185,424 -5,052 10,434 0.5712
2019-08-27 2017-09-30 13F/A-1 MERCK & CO INC COMMON STOCK 58933Y105 190,476 -629 -0.33 12,196 -0.42 0.6980
2017-11-14 2017-09-30 13F MERCK & CO INC COMMON STOCK 58933Y105 192,976 1,871 12,356 0.7017
2017-08-11 2017-06-30 13F MERCK & CO INC COMMON STOCK 58933Y105 191,105 -1,335 -0.69 12,248 0.17 0.7285
2017-05-12 2017-03-31 13F MERCK & CO INC COMMON STOCK 58933Y105 192,440 -802 -0.42 12,227 7.48 0.7399
2017-02-03 2016-12-31 13F MERCK & CO INC COMMON STOCK 58933Y105 193,242 3,877 2.05 11,376 -3.74 0.7133
2016-11-10 2016-09-30 13F MERCK & CO INC COMMON STOCK 58933Y105 189,365 2,056 1.10 11,818 9.52 0.7443
2016-08-10 2016-06-30 13F MERCK & CO INC COMMON STOCK 58933Y105 187,309 -10,409 -5.26 10,791 3.15 0.6856
2016-05-03 2016-03-31 13F MERCK & CO INC COMMON STOCK 58933Y105 197,718 -2,700 -1.35 10,461 -1.18 0.6716
2016-02-12 2015-12-31 13F MERCK & CO INC COMMON STOCK 58933Y105 200,418 8,210 4.27 10,586 11.51 0.6630
2015-11-09 2015-09-30 13F MERCK & CO INC COMMON STOCK 58933Y105 192,208 231 0.12 9,493 -13.14 0.6078
2015-08-25 2015-06-30 13F MERCK & CO INC COMMON STOCK 58933Y105 191,977 -8,859 -4.41 10,929 -5.33 0.6349
2015-05-12 2015-03-31 13F MERCK & CO INC COMMON STOCK 58933Y105 200,836 -1,139 -0.56 11,544 0.65 0.6567
2015-02-17 2014-12-31 13F MERCK & CO INC COMMON STOCK 58933Y105 201,975 1,803 0.90 11,470 -3.34 0.6437
2014-11-14 2014-09-30 13F MERCK & CO INC COMMON 58933Y105 200,172 -2,994 -1.47 11,866 0.96 0.6730
2014-08-07 2014-06-30 13F MERCK & CO INC COMMON 58933Y105 203,166 -5,369 -2.57 11,753 -0.73 0.6480
2014-05-13 2014-03-31 13F MERCK & CO INC COMMON 58933Y105 208,535 -6,556 -3.05 11,839 9.97 0.6626
2014-02-14 2013-12-31 13F MERCK COMMON 58933Y105 215,091 -3,714 -1.70 10,766 3.35 0.6059
2013-11-06 2013-09-30 13F MERCK COMMON 58933Y105 218,805 2,316 1.07 10,417 3.59 0.6420
2013-08-09 2013-06-30 13F MERCK & CO INC COMMON 58933Y105 216,489 -5,007 -2.26 10,056 2.71 0.6502
2013-05-20 2013-03-31 13F MERCK & CO INC COMMON STOCK 58933Y105 221,496 221,496 9,791 0.6317
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.