Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionClear Harbor Asset Management, LLC
Latest Disclosed Ownership44,146 shares
Latest Disclosed Value $ 5,310,429
Clear Harbor Asset Management, LLC ownership in MRK / Merck & Co., Inc.

On May 5, 2026 - Clear Harbor Asset Management, LLC filed a 13F-HR form disclosing ownership of 44,146 shares of Merck & Co., Inc. (MX:MRK) valued at $5,310,429 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 10, 2026 disclosing 42,211 shares of Merck & Co., Inc.. This represents a change in shares of 4.58% during the quarter.

Clear Harbor Asset Management, 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)
2026-05-05 2026-03-31 13F MERCK COM 58933Y105 44,146 1,935 4.58 5,310 19.51 0.3663
2026-02-10 2025-12-31 13F MERCK COM 58933Y105 42,211 -2,011 -4.55 4,443 19.73 0.3006
2025-11-14 2025-09-30 13F/A-1 MERCK COM 58933Y105 44,222 -409 -0.92 3,712 5.07 0.2574
2025-10-23 2025-09-30 13F MERCK COM 58933Y105 44,222 -409 3,712 0.2028
2025-07-14 2025-06-30 13F MERCK COM 58933Y105 44,631 57 0.13 3,533 -11.70 0.2649
2025-05-15 2025-03-31 13F MERCK COM 58933Y105 44,574 -96 -0.21 4,001 -9.97 0.3160
2025-01-17 2024-12-31 13F MERCK COM 58933Y105 44,670 -136 -0.30 4,444 -12.68 0.3542
2024-10-24 2024-09-30 13F MERCK COM 58933Y105 44,806 -67 -0.15 5,088 -8.41 0.4133
2024-07-17 2024-06-30 13F MERCK COM 58933Y105 44,873 -571 -1.26 5,555 -7.35 0.4769
2024-05-10 2024-03-31 13F MERCK COM 58933Y105 45,444 916 2.06 5,996 23.53 0.5240
2024-01-18 2023-12-31 13F MERCK COM 58933Y105 44,528 -205 -0.46 4,854 5.41 0.4453
2023-10-26 2023-09-30 13F MERCK COM 58933Y105 44,733 269 0.60 4,605 -10.23 0.4771
2023-07-21 2023-06-30 13F MERCK COM 58933Y105 44,464 2,477 5.90 5,131 14.84 0.5025
2023-05-04 2023-03-31 13F MERCK COM 58933Y105 41,987 7,974 23.44 4,467 18.39 0.4606
2023-01-20 2022-12-31 13F MERCK COM 58933Y105 34,013 150 0.44 3,774 29.39 0.4710
2022-10-25 2022-09-30 13F MERCK COM 58933Y105 33,863 -529 -1.54 2,916 -7.02 0.4061
2022-07-20 2022-06-30 13F MERCK COM 58933Y105 34,392 49 0.14 3,136 11.28 0.4173
2022-05-10 2022-03-31 13F MERCK COM 58933Y105 34,343 466 1.38 2,818 8.55 0.3191
2022-01-21 2021-12-31 13F MERCK COM 58933Y105 33,877 402 1.20 2,596 3.26 0.2817
2021-11-03 2021-09-30 13F MERCK COM 58933Y105 33,475 -6,212 -15.65 2,514 -18.54 0.0467
2021-08-06 2021-06-30 13F MERCK COM 58933Y105 39,687 -4,677 -10.54 3,086 -9.77 0.3739
2021-04-14 2021-03-31 13F MERCK & CO. COM 58933Y105 44,364 2,898 6.99 3,420 0.83 0.4471
2021-02-04 2020-12-31 13F MERCK & CO. COM 58933Y105 41,466 3,501 9.22 3,392 7.72 0.4872
2020-10-26 2020-09-30 13F MERCK & CO. COM 58933Y105 37,965 570 1.52 3,149 8.89 0.5377
2020-08-05 2020-06-30 13F MERCK & CO. COM 58933Y105 37,395 5,363 16.74 2,892 17.32 0.5476
2020-05-14 2020-03-31 13F/A-1 MERCK & CO. COM 58933Y105 32,032 -3,891 -10.83 2,465 -24.55 0.5746
2020-05-08 2020-03-31 13F MERCK & CO. COM 58933Y105 32,032 -3,891 2,465 584,315.6869
2020-01-29 2019-12-31 13F MERCK COM 58933Y105 35,923 -350 -0.96 3,267 7.01 0.5660
2019-10-31 2019-09-30 13F MERCK COM 58933Y105 36,273 8,464 30.44 3,053 30.92 0.5961
2019-07-22 2019-06-30 13F MERCK COM 58933Y105 27,809 -10,362 -27.15 2,332 -26.55 0.4692
2019-04-19 2019-03-31 13F MERCK COM 58933Y105 38,171 -315 -0.82 3,175 7.96 0.6434
2019-02-11 2018-12-31 13F MERCK COM 58933Y105 38,486 768 2.04 2,941 11.44 0.6763
2018-10-26 2018-09-30 13F MERCK COM 58933Y105 37,718 -570 -1.49 2,639 13.55 0.5320
2018-08-03 2018-06-30 13F MERCK COM 58933Y105 38,288 -240 -0.62 2,324 10.72 0.4341
2018-05-01 2018-03-31 13F MERCK COM 58933Y105 38,528 269 0.70 2,099 -2.51 0.4101
2018-01-23 2017-12-31 13F MERCK COM 58933Y105 38,259 -2,205 -5.45 2,153 -16.90 0.4050
2017-10-25 2017-09-30 13F MERCK COM 58933Y105 40,464 -100 -0.25 2,591 1.73 0.5139
2017-07-25 2017-06-30 13F MERCK COM 58933Y105 40,564 -265 -0.65 2,547 -1.81 0.4871
2017-04-25 2017-03-31 13F MERCK COM 58933Y105 40,829 777 1.94 2,594 10.01 0.5237
2017-01-20 2016-12-31 13F MERCK COM 58933Y105 40,052 -827 -2.02 2,358 -7.57 0.4966
2016-11-07 2016-09-30 13F MERCK COM 58933Y105 40,879 -2,530 -5.83 2,551 2.00 0.5569
2016-08-05 2016-06-30 13F MERCK COM 58933Y105 43,409 -42,331 -49.37 2,501 -44.88 0.5439
2016-05-18 2016-03-31 13F MERCK & CO INC COM 58933Y105 85,740 41,370 93.24 4,537 93.56 0.9977
2016-01-20 2015-12-31 13F MERCK & CO INC COM 58933Y105 44,370 30 0.07 2,344 7.03 0.5326
2015-10-27 2015-09-30 13F MERCK & CO INC COM 58933Y105 44,340 -25,034 -36.09 2,190 -44.54 0.5011
2015-07-23 2015-06-30 13F MERCK & CO INC COM 58933Y105 69,374 -4,172 -5.67 3,949 -6.58 0.7739
2015-04-16 2015-03-31 13F MERCK & CO INC COM 58933Y105 73,546 73,546 0.00 4,227 0.8131
2015-01-30 2014-12-31 13F MERCK & CO INC COM 58933Y105 0 -41,193 -100.00 0 -100.00
2014-10-22 2014-09-30 13F MERCK & CO INC COM 58933Y105 41,193 1,650 4.17 2,442 6.73 0.5422
2014-07-23 2014-06-30 13F MERCK & CO INC COM 58933Y105 39,543 445 1.14 2,288 3.06 0.4896
2014-05-15 2014-03-31 13F MERCK & CO INC COM 58933Y105 39,098 745 1.94 2,220 15.63 0.5200
2014-02-07 2013-12-31 13F MERCK & CO INC COM 58933Y105 38,353 671 1.78 1,920 7.02 0.4825
2013-10-30 2013-09-30 13F MERCK & CO INC COM 58933Y105 37,682 17,105 83.13 1,794 87.66 0.4870
2013-07-19 2013-06-30 13F MERCK & CO INC COM 58933Y105 20,577 20,577 956 0.2833
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
(%)
2020-08-05 2020-06-30 13F MERCK & CO. COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2020-05-14 2020-03-31 13F/A MERCK & CO. COM Call 2,000 -33.33 1 -94.44 n/a n/a n/a
2020-05-08 2020-03-31 13F MERCK & CO. COM Call 2,000 1 n/a n/a n/a
2020-01-29 2019-12-31 13F MERCK COM Call 3,000 18 n/a n/a n/a
2015-10-27 2015-09-30 13F MERCK & CO INC COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2015-07-23 2015-06-30 13F MERCK & CO INC COM Call 40,000 152 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.