Merck & Co., Inc.
US ˙ NYSE ˙ US58933Y1055

SecurityMRK / Merck & Co., Inc.
InstitutionCwm, Llc
Latest Disclosed Ownership1,010,525 shares
Latest Disclosed Value $ 121,556,037
Cwm, Llc ownership in MRK / Merck & Co., Inc.

On May 14, 2026 - Cwm, Llc filed a 13F-HR form disclosing ownership of 1,010,525 shares of Merck & Co., Inc. (US:MRK) valued at $121,556,052 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 26, 2026 disclosing 1,017,023 shares of Merck & Co., Inc.. This represents a change in shares of -0.64% during the quarter. The current value of the position is $115,907,218 USD.

Cwm, 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.

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)
2026-05-14 2026-03-31 13F MERCK COM 58933Y105 1,010,525 -6,498 -0.64 121,556 113,503.74 0.3194
2026-01-26 2025-12-31 13F MERCK COM 58933Y105 1,017,023 61,957 6.49 107 33.75 0.2901
2025-10-15 2025-09-30 13F MERCK COM 58933Y105 955,066 183,089 23.72 80 31.15 0.2411
2025-07-25 2025-06-30 13F MERCK COM 58933Y105 771,977 140,163 22.18 61 8.93 0.2155
2025-05-01 2025-03-31 13F MERCK COM 58933Y105 631,814 21,544 3.53 57 -6.67 0.2262
2025-02-04 2024-12-31 13F MERCK COM 58933Y105 610,270 75,687 14.16 61 0.00 0.2520
2024-10-08 2024-09-30 13F MERCK COM 58933Y105 534,583 12,094 2.31 61 -6.25 0.2611
2024-07-10 2024-06-30 13F MERCK COM 58933Y105 522,489 6,257 1.21 65 -5.88 0.3049
2024-04-05 2024-03-31 13F MERCK COM 58933Y105 516,232 600 0.12 68 21.43 0.3312
2024-02-01 2023-12-31 13F MERCK COM 58933Y105 515,632 6,969 1.37 56 7.69 0.3022
2023-10-11 2023-09-30 13F MERCK COM 58933Y105 508,663 2,277 0.45 52 -10.34 0.3209
2023-08-03 2023-06-30 13F MERCK COM 58933Y105 506,386 6,784 1.36 58 9.43 0.3611
2023-05-01 2023-03-31 13F MERCK COM 58933Y105 499,602 -11,524 -2.25 53 -5.36 0.3591
2023-02-01 2022-12-31 13F MERCK COM 58933Y105 511,126 14,074 2.83 57 -99.87 0.4177
2022-10-27 2022-09-30 13F MERCK COM 58933Y105 497,052 14,514 3.01 42,806 -2.70 0.3400
2022-07-28 2022-06-30 13F MERCK COM 58933Y105 482,538 17,375 3.74 43,993 15.26 0.3408
2022-04-21 2022-03-31 13F MERCK & CO. COM 58933Y105 465,163 64,881 16.21 38,167 24.41 0.2707
2022-01-31 2021-12-31 13F MERCK COM 58933Y105 400,282 21,955 5.80 30,678 4.27 0.2160
2021-09-15 2021-06-30 13F/A-1 MERCK COM 58933Y105 378,327 0 0.00 29,422 0.00 0.2345
2021-07-29 2021-06-30 13F MERCK COM 58933Y105 378,327 0 29,422 0.2345
2021-09-15 2021-03-31 13F/A-1 MERCK COM 58933Y105 378,327 0 0.00 29,422 0.00 0.2345
2021-04-27 2021-03-31 13F MERCK & CO. COM 58933Y105 362,951 -15,376 27,980 0.2461
2021-09-15 2020-12-31 13F/A-1 MERCK COM 58933Y105 378,327 0 0.00 29,422 0.00 0.2345
2021-01-27 2020-12-31 13F MERCK & CO. COM 58933Y105 366,288 -12,039 29,962 0.2808
2021-09-15 2020-09-30 13F/A-1 MERCK COM 58933Y105 378,327 0 0.00 29,422 0.00 0.2345
2020-10-19 2020-09-30 13F MERCK & CO. COM 58933Y105 365,833 -12,494 30,346 0.3374
2021-09-15 2020-06-30 13F/A-1 MERCK COM 58933Y105 378,327 0 0.00 29,422 0.00 0.2345
2020-07-22 2020-06-30 13F MERCK & CO. COM 58933Y105 400,924 22,597 31,003 0.3677
2021-09-15 2020-03-31 13F/A-1 MERCK COM 58933Y105 378,327 0 0.00 29,422 0.00 0.2345
2020-04-28 2020-03-31 13F MERCK & CO. COM 58933Y105 386,710 8,383 29,753 0.4430
2021-09-14 2019-12-31 13F/A-1 MERCK COM 58933Y105 378,327 0 0.00 29,422 0.00 0.2345
2020-01-27 2019-12-31 13F MERCK COM 58933Y105 349,551 -28,776 31,792 0.4062
2021-09-14 2019-09-30 13F/A-1 MERCK COM 58933Y105 378,327 0 0.00 29,422 0.00 0.2345
2019-10-22 2019-09-30 13F MERCK COM 58933Y105 280,508 -97,819 23,613 0.3437
2021-09-14 2019-06-30 13F/A-1 MERCK COM 58933Y105 378,327 0 0.00 29,422 0.00 0.2345
2019-07-31 2019-06-30 13F MERCK COM 58933Y105 33,108 -345,219 2,776 0.0459
2021-09-02 2019-03-31 13F/A-1 MERCK COM 58933Y105 378,327 348,959 1,188.23 29,422 1,211.14 0.2345
2019-04-22 2019-03-31 13F MERCK COM 58933Y105 30,397 1,029 2,528 0.0507
2019-01-25 2018-12-31 13F MERCK COM 58933Y105 29,368 581 2.02 2,244 9.89 0.0560
2018-10-29 2018-09-30 13F MERCK COM 58933Y105 28,787 9,402 48.50 2,042 73.49 0.0521
2018-07-31 2018-06-30 13F MERCK COM 58933Y105 19,385 -615 -3.08 1,177 8.08 0.0387
2018-04-26 2018-03-31 13F MERCK COM 58933Y105 20,000 -77,003 -79.38 1,089 -80.05 0.0433
2018-01-16 2017-12-31 13F MERCK COM 58933Y105 97,003 7,717 8.64 5,458 -4.53 0.2424
2017-10-16 2017-09-30 13F MERCK COM 58933Y105 89,286 -7,273 -7.53 5,717 -7.61 0.2703
2017-07-17 2017-06-30 13F MERCK COM 58933Y105 96,559 -8,342 -7.95 6,188 -7.16 0.3171
2017-04-17 2017-03-31 13F MERCK COM 58933Y105 104,901 -80,495 -43.42 6,665 -38.93 0.3768
2017-01-19 2016-12-31 13F MERCK COM 58933Y105 185,396 -13,991 -7.02 10,914 -12.30 0.6689
2016-10-17 2016-09-30 13F MERCK COM 58933Y105 199,387 -18,941 -8.68 12,444 -1.07 0.8590
2016-07-21 2016-06-30 13F MERCK COM 58933Y105 218,328 -88,483 -28.84 12,578 -22.52 0.9174
2016-04-18 2016-03-31 13F MERCK & CO INC COM 58933Y105 306,811 -22,881 -6.94 16,233 -6.78 1.4255
2016-02-01 2015-12-31 13F MERCK & CO INC COM 58933Y105 329,692 -23,264 -6.59 17,414 -0.11 1.7015
2015-10-30 2015-09-30 13F MERCK & CO INC COM 58933Y105 352,956 12,883 3.79 17,433 -9.95 1.7550
2015-07-09 2015-06-30 13F MERCK & CO INC COM 58933Y105 340,073 7,709 2.32 19,360 1.34 1.8574
2015-04-30 2015-03-31 13F MERCK & CO INC COM 58933Y105 332,364 -27,275 -7.58 19,104 -6.46 1.9345
2015-02-12 2014-12-31 13F MERCK & CO INC COM 58933Y105 359,639 29,056 8.79 20,424 4.22 2.4788
2014-11-14 2014-09-30 13F MERCK & CO INC COM 58933Y105 330,583 88,560 36.59 19,597 39.97 2.8455
2014-08-14 2014-06-30 13F MERCK & CO INC COM 58933Y105 242,023 47,821 24.62 14,001 26.99 2.5053
2014-05-16 2014-03-31 13F MERCK & CO INC COM 58933Y105 194,202 145,368 297.68 11,025 351.10 1.5028
2014-02-14 2013-12-31 13F MERCK & CO INC COM 58933Y105 48,834 31,158 176.27 2,444 190.26 0.3813
2013-11-14 2013-09-30 13F MERCK & CO INC COM 58933Y105 17,676 17,676 842 0.2209
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
(%)
2014-05-16 2014-03-31 13F MERCK & CO INC CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2014-02-14 2013-12-31 13F MERCK & CO INC CALL Call 117 20 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.