Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionPrivate Advisor Group, LLC
Latest Disclosed Ownership273,347 shares
Latest Disclosed Value $ 32,880,963
Private Advisor Group, LLC ownership in MRK / Merck & Co., Inc.

On April 24, 2026 - Private Advisor Group, LLC filed a 13F-HR form disclosing ownership of 273,347 shares of Merck & Co., Inc. (MX:MRK) valued at $32,880,963 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 285,130 shares of Merck & Co., Inc.. This represents a change in shares of -4.13% during the quarter.

Private Advisor Group, LLC has a history of taking positions in derivatives of the underlying security (MRK) in the form of stock options.

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)
2026-04-24 2026-03-31 13F MERCK COM 58933Y105 273,347 -11,783 -4.13 32,881 9.56 0.1460
2026-02-17 2025-12-31 13F MERCK COM 58933Y105 285,130 -14,718 -4.91 30,013 19.26 0.1351
2025-11-13 2025-09-30 13F MERCK COM 58933Y105 299,848 -3,548 -1.17 25,166 4.79 0.1238
2025-08-11 2025-06-30 13F MERCK COM 58933Y105 303,396 -1,640 -0.54 24,017 -12.29 0.1293
2025-05-05 2025-03-31 13F MERCK COM 58933Y105 305,036 -212,759 -41.09 27,380 -46.85 0.1656
2025-02-03 2024-12-31 13F MERCK COM 58933Y105 517,795 206,175 66.16 51,510 45.44 0.2900
2024-10-22 2024-09-30 13F MERCK COM 58933Y105 311,620 -24,960 -7.42 35,416 -14.94 0.2199
2024-08-05 2024-06-30 13F MERCK COM 58933Y105 336,580 13,221 4.09 41,638 -2.41 0.2793
2024-04-30 2024-03-31 13F MERCK COM 58933Y105 323,359 382 0.12 42,667 21.12 0.3066
2024-02-06 2023-12-31 13F MERCK COM 58933Y105 322,977 -19,344 -5.65 35,229 -0.04 0.2739
2023-11-03 2023-09-30 13F MERCK COM 58933Y105 342,321 -25,326 -6.89 35,243 -15.35 0.3149
2023-08-10 2023-06-30 13F MERCK COM 58933Y105 367,647 -769 -0.21 41,634 6.22 0.3619
2023-05-10 2023-03-31 13F MERCK COM 58933Y105 368,416 22,249 6.43 39,196 304.61 0.3743
2023-01-18 2022-12-31 13F MERCK COM 58933Y105 346,167 -8,249 -2.33 9,688 -68.26 0.4878
2022-10-14 2022-09-30 13F MERCK COM 58933Y105 354,416 -42,887 -10.79 30,522 -15.74 0.3508
2022-07-13 2022-06-30 13F MERCK COM 58933Y105 397,303 26,654 7.19 36,222 19.10 0.3231
2022-05-12 2022-03-31 13F/A-1 MERCK COM 58933Y105 370,649 22,844 6.57 30,412 14.09 0.2330
2022-05-10 2022-03-31 13F MERCK COM 58933Y105 347,805 0 26,656 0.2004
2022-02-10 2021-12-31 13F MERCK COM 58933Y105 347,805 -118,699 -25.44 26,656 -23.93 0.2000
2021-10-14 2021-09-30 13F MERCK COM 58933Y105 466,504 183,915 65.08 35,040 59.44 0.2228
2021-08-12 2021-06-30 13F MERCK COM 58933Y105 282,589 -3,271 -1.14 21,977 -0.27 0.1919
2021-04-22 2021-03-31 13F MERCK & CO. COM 58933Y105 285,860 -49,987 -14.88 22,037 -19.79 0.2102
2021-04-01 2020-12-31 13F MERCK & CO. COM 58933Y105 335,847 43,839 15.01 27,473 15.93 0.2863
2020-11-02 2020-09-30 13F MERCK & CO. COM 58933Y105 292,008 3,744 1.30 23,698 6.31 0.3081
2020-08-17 2020-06-30 13F MERCK & CO. COM 58933Y105 288,264 3,536 1.24 22,291 1.76 0.3094
2020-05-12 2020-03-31 13F MERCK & CO. COM 58933Y105 284,728 -8,781 -2.99 21,906 -17.94 0.4021
2020-02-10 2019-12-31 13F MERCK COM 58933Y105 293,509 -9,044 -2.99 26,695 4.66 0.4150
2019-11-13 2019-09-30 13F MERCK COM 58933Y105 302,553 81,266 36.72 25,506 38.24 0.3966
2019-08-14 2019-06-30 13F MERCK COM 58933Y105 221,287 5,310 2.46 18,450 3.40 0.3335
2019-05-13 2019-03-31 13F MERCK COM 58933Y105 215,977 8,505 4.10 17,843 12.64 0.3521
2019-02-08 2018-12-31 13F MERCK COM 58933Y105 207,472 -27,700 -11.78 15,841 -5.05 0.3818
2018-11-01 2018-09-30 13F MERCK COM 58933Y105 235,172 74,665 46.52 16,683 71.83 0.3420
2018-08-09 2018-06-30 13F MERCK COM 58933Y105 160,507 8,550 5.63 9,709 17.27 0.1592
2018-05-09 2018-03-31 13F MERCK COM 58933Y105 151,957 -62,085 -29.01 8,279 -31.64 0.3240
2018-02-07 2017-12-31 13F MERCK COM 58933Y105 214,042 -77,351 -26.55 12,110 -35.36 0.5115
2017-11-13 2017-09-30 13F MERCK COM 58933Y105 291,393 14,374 5.19 18,734 7.43 0.4632
2017-08-10 2017-06-30 13F MERCK COM 58933Y105 277,019 12,012 4.53 17,439 3.53 0.4719
2017-05-10 2017-03-31 13F MERCK COM 58933Y105 265,007 18,614 7.55 16,845 11.74 0.4711
2017-02-09 2016-12-31 13F MERCK COM 58933Y105 246,393 38,817 18.70 15,075 16.29 0.4942
2016-11-10 2016-09-30 13F MERCK COM 58933Y105 207,576 -43,647 -17.37 12,963 -14.07 0.5286
2016-08-09 2016-06-30 13F MERCK COM 58933Y105 251,223 19,549 8.44 15,085 20.14 0.6095
2016-05-13 2016-03-31 13F MERCK & CO INC COM 58933Y105 231,674 -25,534 -9.93 12,556 -7.58 0.6067
2016-02-09 2015-12-31 13F MERCK & CO INC COM 58933Y105 257,208 31,700 14.06 13,586 21.98 0.6515
2015-11-13 2015-09-30 13F MERCK & CO INC COM 58933Y105 225,508 59,867 36.14 11,138 18.11 0.6124
2015-08-13 2015-06-30 13F MERCK & CO INC COM 58933Y105 165,641 17,696 11.96 9,430 10.89 0.4475
2015-05-13 2015-03-31 13F MERCK & CO INC COM 58933Y105 147,945 46,249 45.48 8,504 47.26 0.4901
2015-02-17 2014-12-31 13F MERCK & CO INC COM 58933Y105 101,696 14,243 16.29 5,775 11.40 0.3719
2014-11-12 2014-09-30 13F MERCK & CO INC COM 58933Y105 87,453 7,760 9.74 5,184 12.45 0.3585
2014-08-08 2014-06-30 13F MERCK & CO INC COM 58933Y105 79,693 10,979 15.98 4,610 18.17 0.3965
2014-05-15 2014-03-31 13F MERCK & CO INC COM 58933Y105 68,714 197 0.29 3,901 13.76 0.4112
2014-02-13 2013-12-31 13F MERCK & CO INC COM 58933Y105 68,517 68,517 3,429 0.3829
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
(%)
2024-02-06 2023-12-31 13F MERCK COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2023-11-03 2023-09-30 13F MERCK COM Put 23,700 24 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.