Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionToroso Investments, LLC
Latest Disclosed Ownership895,792 shares
Latest Disclosed Value $ 106,925,337
Toroso Investments, LLC ownership in MRK / Merck & Co., Inc.

On May 15, 2026 - Toroso Investments, LLC filed a 13F-HR form disclosing ownership of 895,792 shares of Merck & Co., Inc. (MX:MRK) valued at $106,925,337 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 305,116 shares of Merck & Co., Inc.. This represents a change in shares of 193.59% during the quarter.

Toroso Investments, LLC has a history of taking positions in derivatives of the underlying security (MRK) in the form of stock options. The firm currently holds call options representing 5,400 of underlying shares valued at $649,566 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

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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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

MX:MRK / Merck & Co., Inc. Historical Put/Call Ratio
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)
2026-05-15 2026-03-31 13F MERCK COM 58933Y105 895,792 590,676 193.59 106,925 232.93 0.1687
2026-02-13 2025-12-31 13F MERCK COM 58933Y105 305,116 -52,481 -14.68 32,117 7.01 0.0762
2025-11-14 2025-09-30 13F MERCK COM 58933Y105 357,597 20,061 5.94 30,013 12.33 0.0600
2025-08-14 2025-06-30 13F MERCK COM 58933Y105 337,536 23,314 7.42 26,719 -5.27 0.1606
2025-05-14 2025-03-31 13F MERCK COM 58933Y105 314,222 -8,969 -2.78 28,205 -12.28 0.2294
2025-02-14 2024-12-31 13F MERCK COM 58933Y105 323,191 33,893 11.72 32,151 -2.13 0.2528
2024-11-25 2024-09-30 13F/A-1 MERCK COM 58933Y105 289,298 55,048 23.50 32,853 13.28 0.3472
2024-11-14 2024-09-30 13F MERCK COM 58933Y105 289,298 55,048 32,853 0.2248
2024-08-14 2024-06-30 13F MERCK COM 58933Y105 234,250 88,289 60.49 29,000 50.59 0.3896
2024-05-16 2024-03-31 13F MERCK COM 58933Y105 145,961 29,533 25.37 19,257 51.73 0.3178
2024-02-15 2023-12-31 13F MERCK COM 58933Y105 116,428 13,640 13.27 12,693 19.94 0.2954
2023-11-15 2023-09-30 13F MERCK COM 58933Y105 102,788 -6,246 -5.73 10,582 88,083.33 0.3219
2023-08-14 2023-06-30 13F MERCK COM 58933Y105 109,034 -4,293 -3.79 13 0.00 0.3698
2023-05-23 2023-03-31 13F/A-1 MERCK COM 58933Y105 113,327 -4,658 -3.95 12 -99.91 0.3969
2023-05-15 2023-03-31 13F MERCK COM 58933Y105 113,327 -4,658 12 0.4279
2023-02-15 2022-12-31 13F MERCK COM 58933Y105 117,985 -14,913 -11.22 13,090 14.37 0.5030
2022-11-23 2022-09-30 13F MERCK COM 58933Y105 132,898 10,492 8.57 11,445 2.55 0.4756
2022-08-15 2022-06-30 13F MERCK COM 58933Y105 122,406 32,318 35.87 11,160 50.97 0.4088
2022-05-20 2022-03-31 13F MERCK COM 58933Y105 90,088 4,386 5.12 7,392 12.55 0.2202
2022-02-16 2021-12-31 13F MERCK COM 58933Y105 85,702 34,233 66.51 6,568 69.89 0.2011
2021-11-15 2021-09-30 13F MERCK COM 58933Y105 51,469 13,752 36.46 3,866 31.81 0.1446
2021-08-13 2021-06-30 13F MERCK COM 58933Y105 37,717 13,180 53.71 2,933 55.02 0.1146
2021-05-17 2021-03-31 13F MERCK & CO. COM 58933Y105 24,537 5,314 27.64 1,892 20.36 0.0885
2021-02-16 2020-12-31 13F MERCK & CO. COM 58933Y105 19,223 3,426 21.69 1,572 20.00 0.1087
2020-11-16 2020-09-30 13F MERCK & CO. COM 58933Y105 15,797 1,666 11.79 1,310 19.85 0.1749
2020-08-17 2020-06-30 13F MERCK & CO. COM 58933Y105 14,131 3,486 32.75 1,093 33.46 0.1484
2020-05-08 2020-03-31 13F MERCK & CO. COM 58933Y105 10,645 4,141 63.67 819 38.34 0.2429
2020-02-14 2019-12-31 13F MERCK COM 58933Y105 6,504 2,003 44.50 592 56.20 0.2495
2019-11-14 2019-09-30 13F MERCK COM 58933Y105 4,501 4,501 379 0.1709
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-15 2026-03-31 13F MERCK COM Call 5,400 145.45 650 180.95 n/a n/a n/a
2026-02-13 2025-12-31 13F MERCK COM Call 2,200 100.00 232 151.09 n/a n/a n/a
2025-11-14 2025-09-30 13F MERCK COM Call 1,100 92 n/a n/a n/a
2025-05-14 2025-03-31 13F MERCK COM Call 0 -100.00 0 n/a n/a n/a
2025-02-14 2024-12-31 13F MERCK COM Call 5 0 n/a n/a n/a
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.