Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionLinden Thomas Advisory Services, LLC
Latest Disclosed Ownership24,524 shares
Latest Disclosed Value $ 2,949,992
Linden Thomas Advisory Services, LLC reports 98.05% increase in ownership of MRK / Merck & Co., Inc.

On April 10, 2026 - Linden Thomas Advisory Services, LLC filed a 13F-HR form disclosing ownership of 24,524 shares of Merck & Co., Inc. (MX:MRK) valued at $2,949,992 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 16, 2026 disclosing 12,383 shares of Merck & Co., Inc.. This represents a change in shares of 98.05% 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.

Upgrade to unlock premium data and export to Excel .

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)
2026-04-10 2026-03-31 13F MERCK COM 58933Y105 24,524 12,141 98.05 2,950 126.32 0.2842
2026-01-16 2025-12-31 13F MERCK COM 58933Y105 12,383 222 1.83 1,303 27.75 0.1321
2025-11-06 2025-09-30 13F MERCK COM 58933Y105 12,161 185 1.54 1,021 7.59 0.1033
2025-07-31 2025-06-30 13F MERCK COM 58933Y105 11,976 317 2.72 948 -9.37 0.1044
2025-04-30 2025-03-31 13F MERCK COM 58933Y105 11,659 726 6.64 1,047 -3.77 0.1355
2025-01-21 2024-12-31 13F MERCK COM 58933Y105 10,933 696 6.80 1,088 -6.45 0.1378
2024-10-17 2024-09-30 13F MERCK COM 58933Y105 10,237 438 4.47 1,163 -4.20 0.1588
2024-07-10 2024-06-30 13F MERCK COM 58933Y105 9,799 737 8.13 1,213 1.51 0.1874
2024-04-30 2024-03-31 13F MERCK COM 58933Y105 9,062 605 7.15 1,196 29.75 0.1921
2024-02-01 2023-12-31 13F MERCK COM 58933Y105 8,457 -262 -3.00 922 2.68 0.1722
2023-10-20 2023-09-30 13F MERCK COM 58933Y105 8,719 8,719 898 0.2000
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.