Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionOrbimed Advisors Llc
ManagerSamuel Isaly
Latest Disclosed Ownership663,400 shares
Latest Disclosed Value $ 79,800,386
Orbimed Advisors Llc ownership in MRK / Merck & Co., Inc.

On May 15, 2026 - Orbimed Advisors Llc filed a 13F-HR form disclosing ownership of 663,400 shares of Merck & Co., Inc. (MX:MRK) valued at $79,800,386 USD as of March 31, 2026. The entity filed a previous 13F-HR on May 15, 2025 disclosing 0 shares of Merck & Co., Inc..

Orbimed Advisors 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 0 of underlying shares valued at $0 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 663,400 663,400 79,800 1.5802
2025-05-15 2025-03-31 13F MERCK COM 58933Y105 0 -829,900 -100.00 0 -100.00
2025-02-14 2024-12-31 13F MERCK COM 58933Y105 829,900 -486,100 -36.94 82,558 -44.76 1.6982
2024-11-14 2024-09-30 13F MERCK COM 58933Y105 1,316,000 0 0.00 149,445 -8.27 2.7154
2024-08-14 2024-06-30 13F MERCK COM 58933Y105 1,316,000 0 0.00 162,921 -6.18 3.2169
2024-05-15 2024-03-31 13F MERCK COM 58933Y105 1,316,000 261,000 24.74 173,646 50.98 3.1804
2024-02-14 2023-12-31 13F MERCK COM 58933Y105 1,055,000 0 0.00 115,016 5.90 2.2970
2023-11-14 2023-09-30 13F MERCK COM 58933Y105 1,055,000 1,055,000 108,612 2.3072
2022-05-16 2022-03-31 13F MERCK COM 58933Y105 0 -1,779,300 -100.00 0 -100.00
2022-02-14 2021-12-31 13F MERCK COM 58933Y105 1,779,300 -1,953,100 -52.33 136,366 -51.36 1.7531
2021-11-15 2021-09-30 13F MERCK COM 58933Y105 3,732,400 0 0.00 280,341 -3.42 3.0809
2021-08-16 2021-06-30 13F MERCK COM 58933Y105 3,732,400 0 0.00 290,269 0.88 2.9359
2021-05-17 2021-03-31 13F MERCK & CO. COM 58933Y105 3,732,400 1,073,100 40.35 287,731 32.27 2.6904
2021-02-16 2020-12-31 13F MERCK & CO. COM 58933Y105 2,659,300 70,200 2.71 217,531 1.29 1.9035
2020-11-16 2020-09-30 13F MERCK & CO. COM 58933Y105 2,589,100 0 0.00 214,766 7.27 2.6994
2020-08-14 2020-06-30 13F MERCK & CO. COM 58933Y105 2,589,100 0 0.00 200,215 0.51 2.8187
2020-05-15 2020-03-31 13F MERCK & CO. COM 58933Y105 2,589,100 635,000 32.50 199,205 12.09 3.3478
2020-02-14 2019-12-31 13F MERCK COM 58933Y105 1,954,100 0 0.00 177,725 8.04 2.5374
2019-11-14 2019-09-30 13F MERCK COM 58933Y105 1,954,100 -616,000 -23.97 164,496 -23.67 3.1214
2019-08-14 2019-06-30 13F MERCK COM 58933Y105 2,570,100 0 0.00 215,503 0.82 3.3375
2019-05-15 2019-03-31 13F MERCK COM 58933Y105 2,570,100 75,100 3.01 213,755 12.12 3.3090
2019-02-14 2018-12-31 13F MERCK COM 58933Y105 2,495,000 -1,049,400 -29.61 190,643 -24.18 3.5253
2018-11-14 2018-09-30 13F MERCK COM 58933Y105 3,544,400 -1,135,600 -24.26 251,440 -11.49 3.0285
2018-08-14 2018-06-30 13F MERCK COM 58933Y105 4,680,000 -608,200 -11.50 284,076 -1.38 3.3881
2018-05-15 2018-03-31 13F MERCK COM 58933Y105 5,288,200 1,662,800 45.87 288,048 41.20 3.5715
2018-02-14 2017-12-31 13F MERCK COM 58933Y105 3,625,400 -1,861,600 -33.93 204,001 -41.94 2.5804
2017-11-14 2017-09-30 13F MERCK COM 58933Y105 5,487,000 0 0.00 351,333 -0.09 3.3576
2017-08-14 2017-06-30 13F MERCK COM 58933Y105 5,487,000 -227,900 -3.99 351,662 -3.16 3.6860
2017-05-15 2017-03-31 13F MERCK COM 58933Y105 5,714,900 1,099,700 23.83 363,125 33.65 4.1160
2017-02-14 2016-12-31 13F MERCK COM 58933Y105 4,615,200 1,108,400 31.61 271,697 24.14 3.4620
2016-11-14 2016-09-30 13F MERCK COM 58933Y105 3,506,800 1,591,300 83.07 218,859 98.33 2.4925
2016-08-15 2016-06-30 13F MERCK COM 58933Y105 1,915,500 1,705,100 810.41 110,352 891.30 1.1515
2016-05-16 2016-03-31 13F MERCK & CO INC COM 58933Y105 210,400 210,400 0.00 11,132 0.1171
2016-02-16 2015-12-31 13F MERCK & CO INC COM 58933Y105 0 -415,000 -100.00 0 -100.00
2015-11-18 2015-09-30 13F/A-1 MERCK & CO INC COM 58933Y105 415,000 0 0.00 20,497 -13.24 0.2069
2015-11-13 2015-09-30 13F MERCK & CO INC COM 58933Y105 415,000 20,497
2015-08-14 2015-06-30 13F MERCK & CO INC COM 58933Y105 415,000 10,000 2.47 23,626 1.49 0.1975
2015-05-15 2015-03-31 13F MERCK & CO INC COM 58933Y105 405,000 -2,510,300 -86.11 23,279 -85.94 0.1987
2015-02-13 2014-12-31 13F MERCK & CO INC COM 58933Y105 2,915,300 253,300 9.52 165,560 4.92 1.5821
2014-11-14 2014-09-30 13F MERCK & CO INC COM 58933Y105 2,662,000 124,000 4.89 157,803 7.48 1.6483
2014-08-14 2014-06-30 13F MERCK & CO INC COM 58933Y105 2,538,000 -9,000 -0.35 146,823 1.54 1.7240
2014-05-15 2014-03-31 13F MERCK & CO INC COM 58933Y105 2,547,000 0 0.00 144,593 13.43 1.7782
2014-02-14 2013-12-31 13F MERCK & CO INC COM 58933Y105 2,547,000 -3,529,000 -58.08 127,477 -55.93 1.8734
2013-11-14 2013-09-30 13F MERCK & CO INC COM 58933Y105 6,076,000 1,950,600 47.28 289,272 50.96 5.1620
2013-08-14 2013-06-30 13F MERCK & CO INC COM 58933Y105 4,125,400 4,125,400 191,625 4.0617
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
(%)
2017-02-14 2016-12-31 13F MERCK COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2016-11-14 2016-09-30 13F MERCK COM Call 350,000 21,847 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.