Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionAdvisor Group Holdings, Inc.
Latest Disclosed Ownership827,246 shares
Latest Disclosed Value $ 99,551,129
Advisor Group Holdings, Inc. ownership in MRK / Merck & Co., Inc.

On May 15, 2026 - Advisor Group Holdings, Inc. filed a 13F-HR form disclosing ownership of 827,246 shares of Merck & Co., Inc. (MX:MRK) valued at $99,551,129 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 808,566 shares of Merck & Co., Inc.. This represents a change in shares of 2.31% during the quarter.

Advisor Group Holdings, Inc. 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 827,246 18,680 2.31 99,551 16.91 0.0848
2026-02-17 2025-12-31 13F MERCK COM 58933Y105 808,566 -93,393 -10.35 85,155 13.39 0.1244
2025-11-14 2025-09-30 13F MERCK COM 58933Y105 901,959 185,903 25.96 75,096 31.61 0.1051
2025-09-04 2025-06-30 13F/A-1 ERCK COM 58933Y105 716,056 64,877 9.96 57,062 -2.43 0.1016
2025-08-13 2025-06-30 13F ERCK COM 58933Y105 663,363 12,184 64,079 0.0741
2025-05-12 2025-03-31 13F MERCK COM 58933Y105 651,179 -113,960 -14.89 58,486 -21.09 0.1303
2025-06-06 2024-12-31 13F/A-1 MERCK COM 58933Y105 765,139 -70,518 -8.44 74,119 -21.92 0.1664
2025-02-07 2024-12-31 13F MERCK COM 58933Y105 741,565 -94,092 79,202 0.2020
2024-11-13 2024-09-30 13F MERCK COM 58933Y105 835,657 -19,330 -2.26 94,933 -10.35 0.2141
2024-08-13 2024-06-30 13F MERCK COM 58933Y105 854,987 -55,213 -6.07 105,887 -11.86 0.2502
2024-05-10 2024-03-31 13F MERCK COM 58933Y105 910,200 -391,914 -30.10 120,135 -15.42 0.2683
2024-02-12 2023-12-31 13F MERCK COM 58933Y105 1,302,114 -452,164 -25.77 142,034 -21.40 0.2485
2023-11-13 2023-09-30 13F MERCK COM 58933Y105 1,754,278 406,440 30.15 180,708 16.55 0.2670
2023-08-21 2023-06-30 13F/A-1 MERCK COM 58933Y105 1,347,838 -46,907 -3.36 155,055 4.00 0.2784
2023-08-10 2023-06-30 13F MERCK COM 58933Y105 2,364,765 970,020 154,038 0.0417
2023-05-12 2023-03-31 13F MERCK COM 58933Y105 1,394,745 1,214 0.09 149,087 -3.61 0.2805
2023-02-10 2022-12-31 13F MERCK COM 58933Y105 1,393,531 65,257 4.91 154,677 35.17 0.3132
2022-11-14 2022-09-30 13F MERCK COM 58933Y105 1,328,274 85,770 6.90 114,431 0.93 0.2616
2022-08-10 2022-06-30 13F MERCK COM 58933Y105 1,242,504 178,776 16.81 113,380 29.90 0.2500
2022-05-04 2022-03-31 13F MERCK COM 58933Y105 1,063,728 39,302 3.84 87,284 11.13 0.1694
2022-02-03 2021-12-31 13F MERCK COM 58933Y105 1,024,426 80,489 8.53 78,545 10.39 0.1487
2021-11-05 2021-09-30 13F MERCK COM 58933Y105 943,937 39,461 4.36 71,153 1.11 0.1483
2021-08-02 2021-06-30 13F MERCK COM 58933Y105 904,476 40,677 4.71 70,371 5.65 0.1523
2021-05-13 2021-03-31 13F MERCK & CO. COM 58933Y105 863,799 33,549 4.04 66,606 -1.94 0.1602
2021-02-10 2020-12-31 13F MERCK & CO. COM 58933Y105 830,250 -5,952 -0.71 67,925 -1.72 0.1814
2020-11-12 2020-09-30 13F MERCK & CO. COM 58933Y105 836,202 59,306 7.63 69,115 14.99 0.2068
2020-08-14 2020-06-30 13F MERCK & CO. COM 58933Y105 776,896 -1,784,692 -69.67 60,103 9.75 0.2017
2020-05-18 2020-03-31 13F MERCK & CO. COM 58933Y105 2,561,588 2,561,588 54,764 0.2242
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
(%)
2022-05-04 2022-03-31 13F MERCK & CO INC CALL COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2022-02-03 2021-12-31 13F MERCK & CO INC CALL COM Call 8 1 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
(%)
2025-05-12 2025-03-31 13F MERCK PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2025-06-06 2024-12-31 13F/A MERCK PUT Put 98 7 n/a n/a n/a
2025-02-07 2024-12-31 13F MERCK PUT Put 98 7 n/a n/a n/a
2021-05-13 2021-03-31 13F MERCK & CO. INC PUT COM Put 0 -100.00 0 n/a n/a n/a
2021-02-10 2020-12-31 13F MERCK & CO. INC PUT COM Put 2 0.00 0 -100.00 n/a n/a n/a
2020-11-12 2020-09-30 13F MERCK & CO. INC PUT COM Put 2 0.00 1 -50.00 n/a n/a n/a
2020-08-14 2020-06-30 13F MERCK & CO. INC PUT COM Put 2 -60.00 2 0.00 n/a n/a n/a
2020-05-18 2020-03-31 13F MERCK & CO. INC PUT COM Put 5 2 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.