Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionHartland & Co., LLC
Latest Disclosed Ownership152,132 shares
Latest Disclosed Value $ 18,299,963
Hartland & Co., LLC reports 37.86% increase in ownership of MRK / Merck & Co., Inc.

On May 6, 2026 - Hartland & Co., LLC filed a 13F-HR form disclosing ownership of 152,132 shares of Merck & Co., Inc. (MX:MRK) valued at $18,299,963 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 9, 2026 disclosing 110,354 shares of Merck & Co., Inc.. This represents a change in shares of 37.86% 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)
2026-05-06 2026-03-31 13F MERCK COM 58933Y105 152,132 41,778 37.86 18,300 57.55 0.1672
2026-02-09 2025-12-31 13F MERCK COM 58933Y105 110,354 -3,044 -2.68 11,616 22.04 0.1464
2025-11-10 2025-09-30 13F MERCK COM 58933Y105 113,398 -3,170 -2.72 9,517 3.14 0.1249
2025-08-08 2025-06-30 13F MERCK COM 58933Y105 116,568 -2,672 -2.24 9,228 -13.78 0.1296
2025-05-13 2025-03-31 13F MERCK COM 58933Y105 119,240 -1,189 -0.99 10,703 -10.67 0.1660
2025-02-10 2024-12-31 13F MERCK COM 58933Y105 120,429 -3,864 -3.11 11,980 -15.12 0.1818
2024-11-13 2024-09-30 13F MERCK COM 58933Y105 124,293 5,206 4.37 14,115 -4.26 0.2190
2024-08-12 2024-06-30 13F MERCK COM 58933Y105 119,087 46,305 63.62 14,743 56.68 0.2515
2024-05-14 2024-03-31 13F MERCK COM 58933Y105 72,782 -303 -0.41 9,410 18.10 0.4658
2024-02-12 2023-12-31 13F MERCK COM 58933Y105 73,085 1,598 2.24 7,968 8.26 0.4228
2023-11-13 2023-09-30 13F/A-1 MERCK COM 58933Y105 71,487 1,103 1.57 7,360 -9.38 0.4521
2023-11-07 2023-09-30 13F MERCK COM 58933Y105 101,381 30,997 10,437 0.5741
2023-08-07 2023-06-30 13F MERCK COM 58933Y105 70,384 2,360 3.47 8,122 12.22 0.4922
2023-05-09 2023-03-31 13F MERCK COM 58933Y105 68,024 483 0.72 7,237 -3.42 0.5267
2023-02-14 2022-12-31 13F MERCK COM 58933Y105 67,541 -824 -1.21 7,494 27.26 0.5870
2022-11-15 2022-09-30 13F MERCK COM 58933Y105 68,365 -24,574 -26.44 5,888 -30.51 0.5425
2022-08-12 2022-06-30 13F MERCK COM 58933Y105 92,939 -225 -0.24 8,473 10.85 0.6604
2022-05-04 2022-03-31 13F MERCK COM 58933Y105 93,164 3,308 3.68 7,644 10.99 0.5186
2022-02-14 2021-12-31 13F MERCK COM 58933Y105 89,856 2,469 2.83 6,887 4.92 0.4683
2021-11-12 2021-09-30 13F MERCK COM 58933Y105 87,387 672 0.77 6,564 -2.67 0.4897
2021-08-12 2021-06-30 13F MERCK COM 58933Y105 86,715 882 1.03 6,744 1.92 0.5190
2021-05-14 2021-03-31 13F MERCK & CO. COM 58933Y105 85,833 16,727 24.20 6,617 17.05 0.5513
2021-02-11 2020-12-31 13F MERCK & CO. COM 58933Y105 69,106 19,182 38.42 5,653 36.51 0.5141
2020-11-12 2020-09-30 13F MERCK & CO. COM 58933Y105 49,924 -2,487 -4.75 4,141 2.17 0.4439
2020-08-11 2020-06-30 13F MERCK & CO. COM 58933Y105 52,411 845 1.64 4,053 2.17 0.4687
2020-05-14 2020-03-31 13F MERCK & CO. COM 58933Y105 51,566 -3,270 -5.96 3,967 -20.45 0.5776
2020-02-11 2019-12-31 13F MERCK COM 58933Y105 54,836 864 1.60 4,987 9.77 0.6051
2019-11-12 2019-09-30 13F MERCK COM 58933Y105 53,972 -537 -0.99 4,543 -0.61 0.6080
2019-08-08 2019-06-30 13F MERCK COM 58933Y105 54,509 1,001 1.87 4,571 2.72 0.6088
2019-05-14 2019-03-31 13F MERCK COM 58933Y105 53,508 2,651 5.21 4,450 14.51 0.6137
2019-02-08 2018-12-31 13F MERCK COM 58933Y105 50,857 1,819 3.71 3,886 11.70 0.6053
2018-11-13 2018-09-30 13F MERCK COM 58933Y105 49,038 1,180 2.47 3,479 19.76 0.4771
2018-08-07 2018-06-30 13F MERCK COM 58933Y105 47,858 1,379 2.97 2,905 14.78 0.4143
2018-05-14 2018-03-31 13F MERCK COM 58933Y105 46,479 4,645 11.10 2,531 7.47 0.3668
2018-02-09 2017-12-31 13F MERCK COM 58933Y105 41,834 -3,465 -7.65 2,355 -18.82 0.3192
2017-11-09 2017-09-30 13F MERCK COM 58933Y105 45,299 741 1.66 2,901 1.58 0.3778
2017-08-03 2017-06-30 13F MERCK COM 58933Y105 44,558 3,861 9.49 2,856 10.44 0.4172
2017-05-11 2017-03-31 13F MERCK COM 58933Y105 40,697 1,339 3.40 2,586 11.61 0.3758
2017-02-10 2016-12-31 13F MERCK COM 58933Y105 39,358 39,358 2,317 0.3749
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.