Merck & Co., Inc.
BG ˙ BUL ˙ US58933Y1055
SecurityBG:6MK / Merck & Co., Inc.
InstitutionHighTower Advisors, LLC
Latest Disclosed Ownership3,635,404 shares
Latest Disclosed Value $ 437,307,312
HighTower Advisors, LLC ownership in 6MK / Merck & Co., Inc.

On May 5, 2026 - HighTower Advisors, LLC filed a 13F-HR form disclosing ownership of 3,635,404 shares of Merck & Co., Inc. (BG:6MK) valued at $437,307,312 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 6, 2026 disclosing 3,818,135 shares of Merck & Co., Inc.. This represents a change in shares of -4.79% during the quarter.

HighTower Advisors, LLC has a history of taking positions in derivatives of the underlying security (6MK) 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.

BG:6MK / 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)
2026-05-05 2026-03-31 13F MERCK COM 58933Y105 3,635,404 -182,731 -4.79 437,307 8.81 0.4641
2026-02-06 2025-12-31 13F MERCK COM 58933Y105 3,818,135 -50,990 -1.32 401,897 23.76 0.4395
2025-11-07 2025-09-30 13F MERCK COM 58933Y105 3,869,125 102,336 2.72 324,738 8.91 0.3687
2025-08-11 2025-06-30 13F MERCK COM 58933Y105 3,766,789 67,829 1.83 298,179 -10.19 0.3735
2025-05-13 2025-03-31 13F MERCK COM 58933Y105 3,698,960 547,085 17.36 332,019 5.89 0.4506
2025-02-07 2024-12-31 13F MERCK COM 58933Y105 3,151,875 282,865 9.86 313,549 -3.75 0.4287
2024-11-14 2024-09-30 13F MERCK COM 58933Y105 2,869,010 126,667 4.62 325,764 -4.01 0.4654
2024-08-13 2024-06-30 13F MERCK COM 58933Y105 2,742,343 38,198 1.41 339,369 -4.91 0.5246
2024-05-06 2024-03-31 13F MERCK COM 58933Y105 2,704,145 -65,477 -2.36 356,895 18.17 0.5781
2024-02-12 2023-12-31 13F MERCK COM 58933Y105 2,769,622 1,494 0.05 302,015 5.96 0.5069
2023-11-08 2023-09-30 13F MERCK COM 58933Y105 2,768,128 29,095 1.06 285,036 -9.87 0.5356
2023-08-14 2023-06-30 13F MERCK COM 58933Y105 2,739,033 43,493 1.61 316,252 10.25 0.6225
2023-05-12 2023-03-31 13F MERCK COM 58933Y105 2,695,540 -230,247 -7.87 286,842 -11.63 0.6258
2023-02-09 2022-12-31 13F MERCK COM 58933Y105 2,925,787 80,118 2.82 324,583 32.43 0.7420
2022-11-09 2022-09-30 13F MERCK COM 58933Y105 2,845,669 -15,407 -0.54 245,089 -6.02 0.6565
2022-08-10 2022-06-30 13F MERCK COM 58933Y105 2,861,076 24,313 0.86 260,778 12.08 0.6737
2022-05-12 2022-03-31 13F MERCK COM 58933Y105 2,836,763 123,627 4.56 232,668 11.87 0.5185
2022-02-10 2021-12-31 13F MERCK COM 58933Y105 2,713,136 293,535 12.13 207,985 14.30 0.4559
2021-11-12 2021-09-30 13F MERCK COM 58933Y105 2,419,601 75,827 3.24 181,971 -0.21 0.4870
2021-08-06 2021-06-30 13F MERCK COM 58933Y105 2,343,774 238,378 11.32 182,350 12.37 0.5280
2021-05-10 2021-03-31 13F MERCK & CO. COM 58933Y105 2,105,396 67,894 3.33 162,278 -2.60 0.5123
2021-02-10 2020-12-31 13F MERCK & CO. COM 58933Y105 2,037,502 99,063 5.11 166,602 3.68 0.6939
2020-11-13 2020-09-30 13F MERCK & CO. COM 58933Y105 1,938,439 70,824 3.79 160,691 11.25 0.7759
2020-08-10 2020-06-30 13F MERCK & CO. COM 58933Y105 1,867,615 106,954 6.07 144,446 6.62 0.7881
2020-05-21 2020-03-31 13F MERCK & CO. COM 58933Y105 1,760,661 -5,202 -0.29 135,479 -15.61 0.8783
2020-02-14 2019-12-31 13F MERCK COM 58933Y105 1,765,863 56,088 3.28 160,544 11.53 0.9488
2019-11-12 2019-09-30 13F MERCK COM 58933Y105 1,709,775 30,390 1.81 143,946 2.18 0.7838
2019-08-13 2019-06-30 13F MERCK COM 58933Y105 1,679,385 -63,742 -3.66 140,869 -2.78 0.8384
2019-05-15 2019-03-31 13F MERCK COM 58933Y105 1,743,127 -29,511 -1.66 144,899 6.96 0.9678
2019-02-14 2018-12-31 13F MERCK COM 58933Y105 1,772,638 13,525 0.77 135,464 8.62 1.0390
2018-11-09 2018-09-30 13F MERCK COM 58933Y105 1,759,113 -59,314 -3.26 124,710 13.08 0.8989
2018-08-14 2018-06-30 13F MERCK COM 58933Y105 1,818,427 19,942 1.11 110,288 12.65 0.8637
2018-05-15 2018-03-31 13F MERCK COM 58933Y105 1,798,485 239,055 15.33 97,907 11.52 0.8202
2018-02-14 2017-12-31 13F MERCK COM 58933Y105 1,559,430 -68,949 -4.23 87,794 -15.75 0.7206
2017-11-14 2017-09-30 13F MERCK COM 58933Y105 1,628,379 44,194 2.79 104,201 2.73 0.8890
2017-09-22 2017-06-30 13F/A-1 MERCK COM 58933Y105 1,584,185 22,213 1.42 101,436 2.21 0.9074
2017-08-14 2017-06-30 13F MERCK COM 58933Y105 1,584,185 22,213 101,436
2017-05-15 2017-03-31 13F MERCK COM 58933Y105 1,561,972 -21,938 -1.39 99,239 6.41 0.9497
2017-02-10 2016-12-31 13F MERCK COM 58933Y105 1,583,910 7,501 0.48 93,260 -5.08 1.0132
2016-11-14 2016-09-30 13F MERCK COM 58933Y105 1,576,409 5,652 0.36 98,255 8.52 1.1384
2016-08-11 2016-06-30 13F MERCK COM 58933Y105 1,570,757 -96,774 -5.80 90,541 2.64 1.1454
2016-05-16 2016-03-31 13F MERCK & CO INC COM 58933Y105 1,667,531 108,195 6.94 88,216 7.12 0.2877
2016-05-18 2015-12-31 13F/A-1 MERCK & CO INC COM 58933Y105 1,559,336 78,379 5.29 82,353 12.63 0.9782
2016-02-12 2015-12-31 13F MERCK & CO INC COM 58933Y105 1,559,336 82,353
2015-11-16 2015-09-30 13F MERCK & CO INC COM 58933Y105 1,480,957 274,745 22.78 73,119 6.36 0.9679
2015-08-11 2015-06-30 13F MERCK & CO INC COM 58933Y105 1,206,212 163,968 15.73 68,746 14.75 1.1017
2015-05-15 2015-03-31 13F MERCK & CO INC COM 58933Y105 1,042,244 29,663 2.93 59,908 4.15 0.8913
2015-02-17 2014-12-31 13F MERCK & CO INC COM 58933Y105 1,012,581 91,784 9.97 57,523 5.40 0.8805
2014-11-14 2014-09-30 13F MERCK & CO INC COM 58933Y105 920,797 14,316 1.58 54,577 4.06 0.9221
2014-08-13 2014-06-30 13F MERCK & CO INC COM 58933Y105 906,481 62,161 7.36 52,449 9.47 0.9099
2014-05-15 2014-03-31 13F MERCK & CO INC COM 58933Y105 844,320 28,877 3.54 47,912 17.39 0.9349
2014-02-14 2013-12-31 13F MERCK & CO INC COM 58933Y105 815,443 82,873 11.31 40,813 16.97 0.8389
2013-11-15 2013-09-30 13F MERCK & CO INC COM 58933Y105 732,570 16,596 2.32 34,891 4.75 0.8734
2013-08-14 2013-06-30 13F MERCK & CO INC COM 58933Y105 715,974 715,974 33,310 0.9060
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
(%)
2025-11-07 2025-09-30 13F MERCK COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2025-08-11 2025-06-30 13F MERCK COM Call 4,000 700.00 5 400.00 n/a n/a n/a
2025-05-13 2025-03-31 13F MERCK COM Call 500 -90.00 1 -50.00 n/a n/a n/a
2025-02-07 2024-12-31 13F MERCK COM Call 5,000 1,150.00 2 n/a n/a n/a
2024-11-14 2024-09-30 13F MERCK COM Call 400 0 n/a n/a n/a
2022-08-10 2022-06-30 13F MERCK COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2022-05-12 2022-03-31 13F MERCK COM Call 2 1 n/a n/a n/a
2021-11-12 2021-09-30 13F MERCK COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2021-08-06 2021-06-30 13F MERCK COM Call 2,000 6 n/a n/a n/a
2021-05-10 2021-03-31 13F MERCK & CO. COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2021-02-10 2020-12-31 13F MERCK & CO. COM Call 5 -99.86 0 -100.00 n/a n/a n/a
2020-11-13 2020-09-30 13F MERCK & CO. COM Call 3,700 1,750.00 3 200.00 n/a n/a n/a
2020-08-10 2020-06-30 13F MERCK & CO. COM Call 200 -94.59 1 -66.67 n/a n/a n/a
2018-11-09 2018-09-30 13F MERCK COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2018-08-14 2018-06-30 13F MERCK COM Call 4,000 6 n/a n/a n/a
2014-08-13 2014-06-30 13F MERCK & CO INC COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2014-05-15 2014-03-31 13F MERCK & CO INC COM Call 500 4 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
(%)
2024-02-12 2023-12-31 13F MERCK COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2023-11-08 2023-09-30 13F MERCK COM Put 234 4 n/a n/a n/a
2023-02-09 2022-12-31 13F MERCK COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2022-11-09 2022-09-30 13F MERCK COM Put 1 1 n/a n/a n/a
2022-05-11 2022-03-31 13F MERCK COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2022-02-10 2021-12-31 13F MERCK COM Put 1 -99.00 4 300.00 n/a n/a n/a
2021-11-12 2021-09-30 13F MERCK COM Put 100 1 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.