Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionSphera Funds Management Ltd.
Latest Disclosed Ownership48,600 shares
Latest Disclosed Value $ 5,846,094
Sphera Funds Management Ltd. ownership in MRK / Merck & Co., Inc.

On May 15, 2026 - Sphera Funds Management Ltd. filed a 13F-HR form disclosing ownership of 48,600 shares of Merck & Co., Inc. (MX:MRK) valued at $5,846,094 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 48,600 shares of Merck & Co., Inc.. This represents a change in shares of 0.00% during the quarter.

Sphera Funds Management Ltd. 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 and put 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 48,600 0 0.00 5,846 14.29 0.8841
2026-02-17 2025-12-31 13F MERCK COM 58933Y105 48,600 0 0.00 5,116 25.43 0.9889
2025-11-14 2025-09-30 13F MERCK COM 58933Y105 48,600 0 0.00 4,079 6.00 0.8604
2025-08-14 2025-06-30 13F MERCK COM 58933Y105 48,600 -11,000 -18.46 3,847 -28.08 0.9028
2025-05-15 2025-03-31 13F MERCK COM 58933Y105 59,600 0 0.00 5,350 -9.78 1.2318
2025-02-14 2024-12-31 13F MERCK COM 58933Y105 59,600 0 0.00 5,929 -12.40 1.0719
2024-11-14 2024-09-30 13F MERCK COM 58933Y105 59,600 0 0.00 6,768 -8.27 1.0771
2024-08-14 2024-06-30 13F MERCK COM 58933Y105 59,600 -44,000 -42.47 7,378 -46.03 1.0063
2024-05-15 2024-03-31 13F MERCK COM 58933Y105 103,600 -20,000 -16.18 13,670 1.45 1.9206
2024-02-15 2023-12-31 13F/A-1 MERCK COM 58933Y105 123,600 0 0.00 13,475 5.89 2.1687
2024-02-14 2023-12-31 13F MERCK COM 58933Y105 123,600 13,475
2023-11-14 2023-09-30 13F MERCK COM 58933Y105 123,600 3,000 2.49 12,725 -8.57 2.3178
2023-08-14 2023-06-30 13F MERCK COM 58933Y105 120,600 0 0.00 13,916 8.46 2.1729
2023-05-15 2023-03-31 13F MERCK COM 58933Y105 120,600 0 0.00 12,831 -4.11 2.1441
2023-02-14 2022-12-31 13F MERCK COM 58933Y105 120,600 -246,400 -67.14 13,381 -57.67 2.8718
2022-11-14 2022-09-30 13F MERCK COM 58933Y105 367,000 82,000 28.77 31,606 21.64 4.3869
2022-08-15 2022-06-30 13F MERCK COM 58933Y105 285,000 6,800 2.44 25,983 13.83 2.7793
2022-05-16 2022-03-31 13F MERCK COM 58933Y105 278,200 -68,223 -19.69 22,826 -14.03 3.2260
2022-02-14 2021-12-31 13F MERCK COM 58933Y105 346,423 346,423 26,550 2.9190
2021-11-15 2021-09-30 13F MERCK COM 58933Y105 0 -772,601 -100.00 0 -100.00
2021-08-17 2021-06-30 13F MERCK COM 58933Y105 772,601 -36,207 -4.48 60,085 -3.63 4.0640
2021-05-17 2021-03-31 13F MERCK & CO. COM 58933Y105 808,808 80,000 10.98 62,351 4.59 4.7823
2021-02-16 2020-12-31 13F MERCK & CO. COM 58933Y105 728,808 -155,000 -17.54 59,616 -18.68 5.2908
2020-11-12 2020-09-30 13F MERCK & CO. COM 58933Y105 883,808 100,000 12.76 73,312 20.95 7.2037
2020-08-13 2020-06-30 13F MERCK & CO. COM 58933Y105 783,808 -84,710 -9.75 60,612 -9.30 5.7002
2020-05-14 2020-03-31 13F MERCK & CO. COM 58933Y105 868,518 313,518 56.49 66,824 32.39 8.3577
2020-02-13 2019-12-31 13F MERCK COM 58933Y105 555,000 85,000 18.09 50,477 27.58 4.1598
2019-11-14 2019-09-30 13F MERCK COM 58933Y105 470,000 18,000 3.98 39,565 4.39 6.1121
2019-08-14 2019-06-30 13F MERCK COM 58933Y105 452,000 75,000 19.89 37,900 20.87 5.1847
2019-05-15 2019-03-31 13F MERCK COM 58933Y105 377,000 -95,000 -20.13 31,355 -13.06 2.8807
2019-02-14 2018-12-31 13F MERCK COM 58933Y105 472,000 -308,000 -39.49 36,066 -34.82 4.0651
2018-11-14 2018-09-30 13F MERCK COM 58933Y105 780,000 100,000 14.71 55,333 34.06 6.3524
2018-08-13 2018-06-30 13F MERCK COM 58933Y105 680,000 100,000 17.24 41,276 30.65 5.6904
2018-05-10 2018-03-31 13F MERCK COM 58933Y105 580,000 155,000 36.47 31,593 32.11 4.7966
2018-02-12 2017-12-31 13F MERCK COM 58933Y105 425,000 0 0.00 23,915 -12.12 2.8062
2017-11-27 2017-09-30 13F/A-1 MERCK COM 58933Y105 425,000 105,000 32.81 27,213 32.69 3.8826
2017-11-09 2017-09-30 13F MERCK COM 58933Y105 425,000 105,000 27,213
2017-08-09 2017-06-30 13F MERCK COM 58933Y105 320,000 25,000 8.47 20,509 9.42 3.4844
2017-05-11 2017-03-31 13F MERCK COM 58933Y105 295,000 -155,000 -34.44 18,744 -29.25 3.6643
2017-02-13 2016-12-31 13F MERCK COM 58933Y105 450,000 150,000 50.00 26,492 41.49 6.7060
2016-11-14 2016-09-30 13F MERCK COM 58933Y105 300,000 200,000 200.00 18,723 225.00 3.0484
2016-08-10 2016-06-30 13F MERCK COM 58933Y105 100,000 100,000 -66.67 5,761 -69.23 1.4957
2016-02-11 2015-12-31 13F Merck COM 58933Y105 0 0 0 0.0000
2015-11-16 2015-09-30 13F MERCK & CO INC COM 58933Y105 0 -400,000 -100.00 0 -100.00
2015-08-06 2015-06-30 13F MERCK & CO INC COM 58933Y105 400,000 25,000 6.67 22,772 5.65 2.2306
2015-05-11 2015-03-31 13F MERCK & CO INC COM 58933Y105 375,000 207,470 123.84 21,555 126.56 2.2441
2015-02-12 2014-12-31 13F Merck COM 058933Y10 167,530 -250,000 -59.88 9,514 -61.56 1.6208
2014-11-20 2014-09-30 13F/A-1 MERCK COM 58933Y105 417,530 -12,470 -2.90 24,751 -0.50 3.0577
2014-11-13 2014-09-30 13F MERCK COM 58933Y105 417,530 24,751
2014-08-20 2014-06-30 13F/A-1 Merck COM 58933Y105 430,000 -100,000 -18.87 24,876 -17.32 6.1305
2014-08-11 2014-06-30 13F Merck COM 58933Y105 430,000 24,876
2014-05-14 2014-03-31 13F Merck COM 58933Y105 530,000 250,000 89.29 30,088 114.70 6.8685
2014-02-13 2013-12-31 13F MERCK & CO INC COM 58933Y105 280,000 280,000 14,014 3.9035
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
(%)
2021-05-17 2021-03-31 13F MERCK & CO. CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2021-02-16 2020-12-31 13F MERCK & CO. CALL Call 130,000 -35.00 10,634 6.23 n/a n/a n/a
2014-02-13 2013-12-31 13F MERCK & CO INC CALL Call 200,000 10,010 n/a n/a n/a
Disclosed Put 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
(%)
2021-11-15 2021-09-30 13F MERCK PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2021-08-17 2021-06-30 13F MERCK PUT Put 772,600 60,085 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.