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

SecurityMRK / Merck & Co., Inc.
InstitutionMackenzie Financial Corp
Latest Disclosed Ownership2,517,435 shares
Latest Disclosed Value $ 302,822,256
Mackenzie Financial Corp ownership in MRK / Merck & Co., Inc.

On May 13, 2026 - Mackenzie Financial Corp filed a 13F-HR form disclosing ownership of 2,517,435 shares of Merck & Co., Inc. (US:MRK) valued at $302,822,256 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 18, 2026 disclosing 1,464,985 shares of Merck & Co., Inc.. This represents a change in shares of 71.84% during the quarter. The current value of the position is $302,746,733 USD.

Mackenzie Financial Corp 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.

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)
2026-05-13 2026-03-31 13F MERCK COM 58933Y105 2,517,435 1,052,450 71.84 302,822 95.28 0.3634
2026-02-18 2025-12-31 13F MERCK COM 58933Y105 1,464,985 290,269 24.71 155,071 57.28 0.1837
2025-11-13 2025-09-30 13F MERCK COM 58933Y105 1,174,716 111,326 10.47 98,594 17.13 0.1194
2025-08-13 2025-06-30 13F MERCK COM 58933Y105 1,063,390 -110,544 -9.42 84,178 -20.11 0.1091
2025-05-07 2025-03-31 13F MERCK COM 58933Y105 1,173,934 -602,919 -33.93 105,372 -40.39 0.1498
2025-05-02 2024-12-31 13F/A-2 MERCK COM 58933Y105 1,776,853 -512,124 -22.37 176,761 -32.00 0.2409
2025-02-20 2024-12-31 13F/A-1 MERCK COM 58933Y105 1,776,853 -512,124 176,761 0.2297
2025-02-14 2024-12-31 13F Merck Common Stock 58933Y105 1,776,853 -512,124 174,073 0.2499
2024-11-13 2024-09-30 13F MERCK COM 58933Y105 2,288,977 -50,129 -2.14 259,936 -10.24 0.3617
2024-08-14 2024-06-30 13F MERCK COM 58933Y105 2,339,106 149,979 6.85 289,581 0.25 0.4303
2024-05-10 2024-03-31 13F MERCK COM 58933Y105 2,189,127 193,843 9.72 288,855 32.79 0.4163
2024-01-30 2023-12-31 13F MERCK COM 58933Y105 1,995,284 299,077 17.63 217,526 26.01 0.3281
2023-10-25 2023-09-30 13F MERCK COM 58933Y105 1,696,207 -65,907 -3.74 172,623 -14.32 0.2902
2023-08-03 2023-06-30 13F MERCK COM 58933Y105 1,762,114 -775,785 -30.57 201,462 -25.39 0.3056
2023-04-24 2023-03-31 13F MERCK COM 58933Y105 2,537,899 47,005 1.89 270,007 -2.30 0.4171
2023-02-14 2022-12-31 13F MERCK COM 58933Y105 2,490,894 12,531 0.51 276,365 29.48 0.4616
2022-10-07 2022-09-30 13F Merck Common Stock 58933Y105 2,478,363 99,935 4.20 213,437 -1.57 0.3671
2022-08-10 2022-06-30 13F MERCK COM 58933Y105 2,378,428 230,261 10.72 216,841 23.03 0.3473
2022-05-13 2022-03-31 13F MERCK COM 58933Y105 2,148,167 2,460 0.11 176,257 7.18 0.2363
2022-02-14 2021-12-31 13F MERCK COM 58933Y105 2,145,707 160,345 8.08 164,447 10.28 0.2216
2021-11-08 2021-09-30 13F MERCK COM 58933Y105 1,985,362 72,702 3.80 149,121 0.25 0.2115
2021-08-11 2021-06-30 13F MERCK COM 58933Y105 1,912,660 -40,979 -2.10 148,748 -1.23 0.2069
2021-05-14 2021-03-31 13F MERCK & CO. COM 58933Y105 1,953,639 -203,456 -9.43 150,606 -14.65 0.2295
2021-02-10 2020-12-31 13F MERCK & CO. COM 58933Y105 2,157,095 -149,471 -6.48 176,450 -7.78 0.3810
2020-11-13 2020-09-30 13F MERCK & CO. COM 58933Y105 2,306,566 457,228 24.72 191,330 33.79 0.4753
2020-08-13 2020-06-30 13F MERCK & CO. COM 58933Y105 1,849,338 -8,155 -0.44 143,009 0.07 0.3827
2020-05-14 2020-03-31 13F MERCK & CO. COM 58933Y105 1,857,493 538,634 40.84 142,916 19.15 0.4595
2020-02-13 2019-12-31 13F MERCK COM 58933Y105 1,318,859 123,918 10.37 119,950 19.25 0.2950
2019-11-14 2019-09-30 13F MERCK COM 58933Y105 1,194,941 10,544 0.89 100,590 1.29 0.2644
2019-08-23 2019-06-30 13F/A-1 MERCK COM 58933Y105 1,184,397 705,176 147.15 99,312 149.17 0.2562
2019-08-14 2019-06-30 13F MERCK COM 58933Y105 1,184,397 705,176 99,312
2019-05-15 2019-03-31 13F MERCK COM 58933Y105 479,221 -567,481 -54.22 39,857 -50.17 0.0962
2019-02-06 2018-12-31 13F MERCK COM 58933Y105 1,046,702 -167,694 -13.81 79,978 -7.16 0.2102
2018-11-15 2018-09-30 13F MERCK COM 58933Y105 1,214,396 -672,127 -35.63 86,149 -24.77 0.2096
2018-08-13 2018-06-30 13F MERCK COM 58933Y105 1,886,523 -3,643,055 -65.88 114,512 -61.98 0.2922
2018-05-14 2018-03-31 13F/A-1 MERCK COM 58933Y105 5,529,578 -411,576 -6.93 301,196 -9.90 0.7677
2018-05-14 2018-03-31 13F MERCK COM 58933Y105 5,529,578 301,196
2018-02-13 2017-12-31 13F MERCK COM 58933Y105 5,941,154 5,923,357 33,282.90 334,309 29,225.35 0.8070
2017-11-13 2017-09-30 13F MERCK COM 58933Y105 17,797 631 3.68 1,140 3.64 0.0061
2017-08-14 2017-06-30 13F MERCK COM 58933Y105 17,166 1,136 7.09 1,100 7.95 0.0061
2017-05-25 2017-03-31 13F/A-1 MERCK COM 58933Y105 16,030 -4,127 -20.47 1,019 -14.15 0.0060
2017-05-12 2017-03-31 13F MERCK COM 58933Y105 16,030 1,019
2017-02-14 2016-12-31 13F MERCK COM 58933Y105 20,157 899 4.67 1,187 -1.25 0.0071
2016-11-15 2016-09-30 13F MERCK COM 58933Y105 19,258 -145,831 -88.33 1,202 -87.36 0.0075
2016-08-12 2016-06-30 13F MERCK COM 58933Y105 165,089 14,730 9.80 9,511 19.56 0.0537
2016-05-12 2016-03-31 13F MERCK & CO INC COM 58933Y105 150,359 -10,207 -6.36 7,955 -6.20 0.0722
2016-02-12 2015-12-31 13F MERCK & CO INC COM 58933Y105 160,566 11,881 7.99 8,481 15.48 0.0526
2015-11-13 2015-09-30 13F MERCK & CO INC COM 58933Y105 148,685 10,164 7.34 7,344 -6.87 0.0446
2015-08-13 2015-06-30 13F MERCK & CO INC COM 58933Y105 138,521 -142 -0.10 7,886 -1.05 0.0428
2015-05-13 2015-03-31 13F MERCK & CO INC COM 58933Y105 138,663 -1,092 -0.78 7,970 0.42 0.0420
2015-02-11 2014-12-31 13F MERCK & CO INC COM 58933Y105 139,755 7,849 5.95 7,937 1.51 0.0405
2014-11-12 2014-09-30 13F MERCK & CO INC COM 58933Y105 131,906 -14,458 -9.88 7,819 -7.65 0.0392
2014-08-11 2014-06-30 13F MERCK & CO INC COM 58933Y105 146,364 23,502 19.13 8,467 21.39 0.0394
2014-05-14 2014-03-31 13F MERCK & CO INC COM 58933Y105 122,862 -6,948 -5.35 6,975 7.36 0.0342
2014-02-11 2013-12-31 13F/A-1 MERCK & CO INC COM 58933Y105 129,810 -1,175 -0.90 6,497 4.19 0.0328
2014-02-03 2013-12-31 13F MERCK & CO INC COM 58933Y105 129,810 6,497
2013-11-12 2013-09-30 13F MERCK & CO INC COM 58933Y105 130,985 13,423 11.42 6,236 14.19 0.0316
2013-08-20 2013-06-30 13F/A-1 MERCK & CO INC COM 58933Y105 117,562 117,562 5,461 0.0260
2013-08-09 2013-06-30 13F MERCK & CO INC COM 58933Y105 117,562 5,461 0.0261
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
(%)
2026-02-18 2025-12-31 13F MERCK COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2025-11-13 2025-09-30 13F MERCK COM Put 12,300 26 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.