Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionGuggenheim Capital Llc
Latest Disclosed Ownership794,868 shares
Latest Disclosed Value $ 95,614,672
Guggenheim Capital Llc reports 2.73% increase in ownership of MRK / Merck & Co., Inc.

On May 15, 2026 - Guggenheim Capital Llc filed a 13F-HR form disclosing ownership of 794,868 shares of Merck & Co., Inc. (MX:MRK) valued at $95,614,672 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 773,718 shares of Merck & Co., Inc.. This represents a change in shares of 2.73% during the quarter.

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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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 794,868 21,150 2.73 95,615 17.40 0.3694
2026-02-17 2025-12-31 13F MERCK COM 58933Y105 773,718 59,725 8.36 81,442 35.90 0.2911
2025-11-13 2025-09-30 13F MERCK COM 58933Y105 713,993 100,798 16.44 59,925 23.45 0.4349
2025-08-13 2025-06-30 13F MERCK COM 58933Y105 613,195 113,220 22.65 48,541 8.16 0.3852
2025-05-14 2025-03-31 13F MERCK COM 58933Y105 499,975 112,579 29.06 44,878 16.45 0.4122
2025-02-13 2024-12-31 13F MERCK COM 58933Y105 387,396 28,910 8.06 38,538 -5.33 0.3124
2024-11-13 2024-09-30 13F MERCK COM 58933Y105 358,486 -35,872 -9.10 40,710 -16.62 0.2849
2024-08-14 2024-06-30 13F MERCK COM 58933Y105 394,358 -55,875 -12.41 48,822 -17.82 0.3462
2024-05-14 2024-03-31 13F MERCK COM 58933Y105 450,233 -112,727 -20.02 59,408 -3.20 0.4186
2024-02-14 2023-12-31 13F MERCK COM 58933Y105 562,960 -39,715 -6.59 61,374 -1.08 0.4638
2023-11-14 2023-09-30 13F MERCK COM 58933Y105 602,675 -136,123 -18.42 62,045 -27.22 0.5334
2023-08-11 2023-06-30 13F MERCK COM 58933Y105 738,798 -103,694 -12.31 85,250 -4.89 0.6692
2023-05-11 2023-03-31 13F MERCK COM 58933Y105 842,492 -88,587 -9.51 89,633 -13.23 0.7544
2023-02-14 2022-12-31 13F MERCK COM 58933Y105 931,079 -69,545 -6.95 103,303 19.88 0.9074
2022-11-14 2022-09-30 13F MERCK COM 58933Y105 1,000,624 -244 -0.02 86,174 -5.56 0.7892
2022-08-15 2022-06-30 13F MERCK COM 58933Y105 1,000,868 5,949 0.60 91,249 11.78 0.7203
2022-05-16 2022-03-31 13F MERCK COM 58933Y105 994,919 78,527 8.57 81,633 16.23 0.4910
2022-02-14 2021-12-31 13F MERCK COM 58933Y105 916,392 39,983 4.56 70,231 6.69 0.3663
2021-11-15 2021-09-30 13F MERCK COM 58933Y105 876,409 110,834 14.48 65,827 10.56 0.3952
2021-08-13 2021-06-30 13F MERCK COM 58933Y105 765,575 84,133 12.35 59,539 13.34 0.3505
2021-05-13 2021-03-31 13F MERCK & CO. COM 58933Y105 681,442 76,822 12.71 52,532 6.21 0.3449
2021-02-16 2020-12-31 13F MERCK & CO. COM 58933Y105 604,620 76,114 14.40 49,459 12.82 0.3101
2020-11-13 2020-09-30 13F MERCK & CO. COM 58933Y105 528,506 75,059 16.55 43,840 25.02 0.3173
2020-08-14 2020-06-30 13F MERCK & CO. COM 58933Y105 453,447 12,937 2.94 35,066 3.46 0.2713
2020-06-02 2020-03-31 13F MERCK & CO. COM 58933Y105 440,510 -80,522 -15.45 33,893 -28.48 0.3413
2020-02-20 2019-12-31 13F/A-1 MERCK COM 58933Y105 521,032 9,097 1.78 47,387 9.96 0.3559
2020-02-14 2019-12-31 13F MERCK COM 58933Y105 521,032 9,097 47,387 280,853.2767
2020-02-20 2019-09-30 13F/A-1 MERCK COM 58933Y105 511,935 -43,049 -7.76 43,094 -7.40 0.3444
2019-11-14 2019-09-30 13F MERCK COM 58933Y105 511,935 -43,049 43,094 315,805.4725
2019-08-14 2019-06-30 13F MERCK COM 58933Y105 554,984 -5,791 -1.03 46,536 -0.22 0.3787
2019-05-15 2019-03-31 13F MERCK COM 58933Y105 560,775 -124,161 -18.13 46,640 -10.88 0.3801
2019-02-14 2018-12-31 13F MERCK COM 58933Y105 684,936 38,854 6.01 52,336 14.19 0.4435
2018-11-14 2018-09-30 13F MERCK COM 58933Y105 646,082 97,030 17.67 45,833 37.53 0.2987
2018-08-14 2018-06-30 13F MERCK COM 58933Y105 549,052 -1,058,945 -65.85 33,325 -61.95 0.2224
2018-05-15 2018-03-31 13F MERCK COM 58933Y105 1,607,997 67,331 4.37 87,587 1.03 0.2137
2018-02-14 2017-12-31 13F MERCK COM 58933Y105 1,540,666 138,831 9.90 86,694 -3.42 0.2054
2017-11-14 2017-09-30 13F MERCK COM 58933Y105 1,401,835 18,424 1.33 89,760 1.24 0.2108
2017-08-14 2017-06-30 13F MERCK COM 58933Y105 1,383,411 -3,627 -0.26 88,662 0.60 0.2348
2017-05-15 2017-03-31 13F MERCK COM 58933Y105 1,387,038 -66,779 -4.59 88,133 2.97 0.2389
2017-02-14 2016-12-31 13F MERCK COM 58933Y105 1,453,817 242,679 20.04 85,587 13.23 0.2448
2016-11-14 2016-09-30 13F MERCK COM 58933Y105 1,211,138 -145,599 -10.73 75,587 -3.29 0.2351
2016-08-15 2016-06-30 13F MERCK COM 58933Y105 1,356,737 -247,056 -15.40 78,161 -7.89 0.2455
2016-05-16 2016-03-31 13F MERCK & CO INC COM 58933Y105 1,603,793 64,262 4.17 84,857 4.35 0.2677
2016-02-16 2015-12-31 13F MERCK & CO INC COM 58933Y105 1,539,531 133,748 9.51 81,320 17.12 0.2366
2015-11-16 2015-09-30 13F MERCK & CO INC COM 58933Y105 1,405,783 -167,070 -10.62 69,432 -22.46 0.2137
2015-08-14 2015-06-30 13F MERCK & CO INC COM 58933Y105 1,572,853 -126,401 -7.44 89,544 -8.33 0.2210
2015-05-18 2015-03-31 13F/A-1 MERCK & CO INC COM 58933Y105 1,699,254 290,426 20.61 97,676 22.08 0.2312
2015-05-15 2015-03-31 13F MERCK & CO INC COM 58933Y105 1,699,254 97,676
2015-02-17 2014-12-31 13F MERCK & CO INC COM 58933Y105 1,408,828 21,913 1.58 80,008 -2.68 0.2007
2014-11-14 2014-09-30 13F MERCK & CO INC COM 58933Y105 1,386,915 57,798 4.35 82,215 6.92 0.1983
2014-08-14 2014-06-30 13F MERCK & CO INC COM 58933Y105 1,329,117 -90,515 -6.38 76,892 -4.59 0.1945
2014-05-16 2014-03-31 13F MERCK & CO INC COM 58933Y105 1,419,632 -90,974 -6.02 80,593 6.60 0.2292
2014-02-14 2013-12-31 13F MERCK & CO INC COM 58933Y105 1,510,606 95,684 6.76 75,606 12.23 0.2297
2013-11-14 2013-09-30 13F MERCK & CO INC COM 58933Y105 1,414,922 -1,636 -0.12 67,368 2.39 0.2419
2013-08-22 2013-06-30 13F/A-1 MERCK & CO INC COM 58933Y105 1,416,558 1,416,558 65,796 0.2767
2013-08-14 2013-06-30 13F MERCK & CO INC COM 58933Y105 1,420,417 66,026 0.2784
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.