Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionWestern Wealth Management, LLC
Latest Disclosed Ownership31,978 shares
Latest Disclosed Value $ 3,846,620
Western Wealth Management, LLC reports 43.79% increase in ownership of MRK / Merck & Co., Inc.

On May 19, 2026 - Western Wealth Management, LLC filed a 13F-HR form disclosing ownership of 31,978 shares of Merck & Co., Inc. (MX:MRK) valued at $3,846,620 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 5, 2026 disclosing 22,239 shares of Merck & Co., Inc.. This represents a change in shares of 43.79% 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)
2026-05-19 2026-03-31 13F MERCK COM 58933Y105 31,978 9,739 43.79 3,847 64.36 0.0894
2026-02-05 2025-12-31 13F MERCK Common Stock 58933Y105 22,239 2,571 13.07 2,341 41.82 0.1078
2025-11-06 2025-09-30 13F MERCK Common Stock 58933Y105 19,668 151 0.77 1,651 6.80 0.0871
2025-08-11 2025-06-30 13F MERCK Common Stock 58933Y105 19,517 -1,031 -5.02 1,545 -16.21 0.0917
2025-04-23 2025-03-31 13F MERCK Common Stock 58933Y105 20,548 -870 -4.06 1,844 -13.43 0.1221
2025-04-16 2024-12-31 13F/A-1 MERCK Common Stock 58933Y105 21,418 -7,303 -25.43 2,131 -34.68 0.1388
2025-02-18 2024-12-31 13F MERCK COM 58933Y105 7,677 -21,044 764 0.2293
2024-11-12 2024-09-30 13F MERCK COM 58933Y105 28,721 5,925 25.99 3,262 15.56 0.1859
2024-07-19 2024-06-30 13F MERCK COM 58933Y105 22,796 -139 -0.61 2,822 -6.74 0.2092
2024-05-03 2024-03-31 13F MERCK COM 58933Y105 22,935 -6,359 -21.71 3,026 -5.23 0.2352
2024-01-31 2023-12-31 13F MERCK COM 58933Y105 29,294 472 1.64 3,194 7.62 0.2302
2023-11-08 2023-09-30 13F MERCK COM 58933Y105 28,822 1,357 4.94 2,967 -6.37 0.2507
2023-08-30 2023-06-30 13F MERCK COM 58933Y105 27,465 755 2.83 3,169 11.55 0.2703
2023-08-30 2023-03-31 13F MERCK COM 58933Y105 26,710 45 0.17 2,842 -3.96 0.2645
2023-02-03 2022-12-31 13F MERCK COM 58933Y105 26,665 -23,215 -46.54 2,959 -32.43 0.3024
2022-11-07 2022-09-30 13F MERCK COM 58933Y105 49,880 2,163 4.53 4,378 0.48 0.2507
2022-07-18 2022-06-30 13F MERCK COM 58933Y105 47,717 -3,009 -5.93 4,357 4.71 0.2501
2022-05-10 2022-03-31 13F MERCK COM 58933Y105 50,726 23,394 85.59 4,161 98.52 0.2019
2022-02-14 2021-12-31 13F MERCK COM 58933Y105 27,332 187 0.69 2,096 -0.76 0.2069
2021-08-09 2021-06-30 13F MERCK COM 58933Y105 27,145 6,239 29.84 2,112 31.02 0.2172
2021-05-14 2021-03-31 13F MERCK & CO. COM 58933Y105 20,906 2,493 13.54 1,612 7.04 0.2167
2021-02-10 2020-12-31 13F MERCK & CO. COM 58933Y105 18,413 -3,660 -16.58 1,506 -17.75 0.2210
2020-10-27 2020-09-30 13F MERCK & CO. COM 58933Y105 22,073 1,258 6.04 1,831 13.66 0.2991
2020-07-20 2020-06-30 13F MERCK & CO. COM 58933Y105 20,815 1,880 9.93 1,611 10.72 0.2921
2020-04-27 2020-03-31 13F MERCK & CO. COM 58933Y105 18,935 1,383 7.88 1,455 -8.83 0.3337
2020-02-10 2019-12-31 13F MERCK COM 58933Y105 17,552 -2,240 -11.32 1,596 -4.14 0.2418
2019-11-08 2019-09-30 13F MERCK COM 58933Y105 19,792 -375 -1.86 1,665 -1.65 0.3465
2019-08-06 2019-06-30 13F MERCK COM 58933Y105 20,167 908 4.71 1,693 5.81 0.2224
2019-05-10 2019-03-31 13F MERCK COM 58933Y105 19,259 2,178 12.75 1,600 22.70 0.3561
2019-02-15 2018-12-31 13F MERCK COM 58933Y105 17,081 17,081 1,304 0.3508
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.