Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionNew England Research & Management, Inc.
Latest Disclosed Ownership26,529 shares
Latest Disclosed Value $ 3,191,173
New England Research & Management, Inc. reports 9.27% decrease in ownership of MRK / Merck & Co., Inc.

On May 7, 2026 - New England Research & Management, Inc. filed a 13F-HR form disclosing ownership of 26,529 shares of Merck & Co., Inc. (MX:MRK) valued at $3,191,173 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 7, 2026 disclosing 29,238 shares of Merck & Co., Inc.. This represents a change in shares of -9.27% 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)
2026-05-07 2026-03-31 13F MERCK COM 58933Y105 26,529 -2,709 -9.27 3,191 3.70 1.3486
2026-01-07 2025-12-31 13F MERCK COM 58933Y105 29,238 7,642 35.39 3,078 69.81 1.3462
2025-10-06 2025-09-30 13F Merck CS 58933Y105 21,596 -809 -3.61 1,813 181,100.00 0.8326
2025-07-09 2025-06-30 13F Merck CS 58933Y105 22,405 -2,650 -10.58 2 -50.00 0.8427
2025-04-16 2025-03-31 13F Merck CS 58933Y105 25,055 895 3.70 2 0.00 1.1424
2025-01-23 2024-12-31 13F Merck CS 58933Y105 24,160 417 1.76 2 0.00 1.2228
2024-10-07 2024-09-30 13F Merck CS 58933Y105 23,743 5,425 29.62 3 0.00 1.2654
2024-07-09 2024-06-30 13F Merck CS 58933Y105 18,318 2,519 15.94 2 0.00 1.0893
2024-04-16 2024-03-31 13F Merck CS 58933Y105 15,799 475 3.10 2 100.00 1.0232
2024-02-06 2023-12-31 13F Merck CS 58933Y105 15,324 -600 -3.77 2 0.00 0.8851
2023-10-10 2023-09-30 13F Merck CS 58933Y105 15,924 -400 -2.45 2 0.00 0.9339
2023-07-05 2023-06-30 13F Merck CS 58933Y105 16,324 -149 -0.90 2 0.00 1.0929
2023-04-06 2023-03-31 13F Merck CS 58933Y105 16,473 -11,394 -40.89 2 -66.67 1.0283
2023-01-09 2022-12-31 13F Merck CS 58933Y105 27,867 -3,492 -11.14 3 -99.89 1.7768
2022-10-06 2022-09-30 13F Merck CS 58933Y105 31,359 1,925 6.54 2,701 0.67 1.7017
2022-07-20 2022-06-30 13F Merck CS 58933Y105 29,434 2,849 10.72 2,683 23.02 1.5621
2022-04-20 2022-03-31 13F Merck CS 58933Y105 26,585 -424 -1.57 2,181 5.36 1.1313
2022-01-05 2021-12-31 13F Merck CS 58933Y105 27,009 -959 -3.43 2,070 -1.48 1.0010
2021-10-08 2021-09-30 13F Merck CS 58933Y105 27,968 -50 -0.18 2,101 -3.58 1.1005
2021-07-15 2021-06-30 13F Merck CS 58933Y105 28,018 -3,803 -11.95 2,179 -11.17 1.1270
2021-04-16 2021-03-31 13F Merck CS 58933Y105 31,821 2,413 8.21 2,453 1.95 1.3449
2021-01-07 2020-12-31 13F Merck CS 58933Y105 29,408 -14 -0.05 2,406 -1.43 1.4882
2020-10-08 2020-09-30 13F Merck CS 58933Y105 29,422 -5,648 -16.10 2,441 -9.99 1.7676
2020-07-15 2020-06-30 13F Merck CS 58933Y105 35,070 8,850 33.75 2,712 34.46 1.9407
2020-06-15 2020-03-31 13F Merck CS 58933Y105 26,220 3,100 13.41 2,017 -4.09 1.7222
2020-01-14 2019-12-31 13F Merck CS 58933Y105 23,120 -175 -0.75 2,103 7.24 1.4090
2019-11-04 2019-09-30 13F Merck CS 58933Y105 23,295 -450 -1.90 1,961 -1.51 1.4204
2019-07-09 2019-06-30 13F Merck CS 58933Y105 23,745 -550 -2.26 1,991 -1.48 1.3510
2019-04-03 2019-03-31 13F Merck CS 58933Y105 24,295 -3,720 -13.28 2,021 -5.60 1.3652
2019-01-11 2018-12-31 13F Merck CS 58933Y105 28,015 -600 -2.10 2,141 5.47 1.6844
2018-10-03 2018-09-30 13F Merck CS 58933Y105 28,615 -1,250 -4.19 2,030 11.97 1.3204
2018-07-05 2018-06-30 13F Merck CS 58933Y105 29,865 -1,800 -5.68 1,813 5.10 1.1987
2018-04-17 2018-03-31 13F Merck CS 58933Y105 31,665 4,000 14.46 1,725 10.79 1.1559
2018-01-09 2017-12-31 13F Merck CS 58933Y105 27,665 1,650 6.34 1,557 -6.54 1.1142
2017-10-25 2017-09-30 13F Merck CS 58933Y105 26,015 12,050 86.29 1,666 86.15 1.2207
2017-07-11 2017-06-30 13F Merck CS 58933Y105 13,965 0 0.00 895 0.90 0.6623
2017-04-07 2017-03-31 13F Merck CS 58933Y105 13,965 -45 -0.32 887 7.52 0.6822
2017-02-06 2016-12-31 13F Merck CS 58933Y105 14,010 88 0.63 825 -5.06 0.6476
2016-10-05 2016-09-30 13F Merck CS 58933Y105 13,922 -24,202 -63.48 869 -60.43 0.7285
2016-07-05 2016-06-30 13F Merck CS 58933Y105 38,124 -500 -1.29 2,196 7.44 1.8902
2016-04-06 2016-03-31 13F Merck CS 58933Y105 38,624 600 1.58 2,044 1.79 1.7378
2016-01-08 2015-12-31 13F Merck CS 58933Y105 38,024 480 1.28 2,008 8.31 1.7366
2015-10-06 2015-09-30 13F Merck CS 58933Y105 37,544 4,775 14.57 1,854 -0.64 1.7642
2015-07-07 2015-06-30 13F Merck CS 58933Y105 32,769 9,327 39.79 1,866 38.53 1.5289
2015-04-06 2015-03-31 13F Merck CS 58933Y105 23,442 2,774 13.42 1,347 14.74 1.1580
2015-01-21 2014-12-31 13F Merck CS 58933Y105 20,668 1,332 6.89 1,174 2.44 1.0069
2014-10-15 2014-09-30 13F Merck CS 58933Y105 19,336 -900 -4.45 1,146 -2.13 1.0004
2014-07-01 2014-06-30 13F Merck CS 58933Y105 20,236 -350 -1.70 1,171 0.17 1.0487
2014-04-16 2014-03-31 13F Merck CS 58933Y105 20,586 -8,450 -29.10 1,169 -19.55 1.0710
2014-01-08 2013-12-31 13F Merck CS 58933Y105 29,036 29,036 1,453 1.4019
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.