Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionCHICAGO TRUST Co NA
Latest Disclosed Ownership43,814 shares
Latest Disclosed Value $ 5,270,386
CHICAGO TRUST Co NA reports 12.52% decrease in ownership of MRK / Merck & Co., Inc.

On April 24, 2026 - CHICAGO TRUST Co NA filed a 13F-HR form disclosing ownership of 43,814 shares of Merck & Co., Inc. (MX:MRK) valued at $5,270,386 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 50,082 shares of Merck & Co., Inc.. This represents a change in shares of -12.52% 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)
2026-04-24 2026-03-31 13F MERCK COM 58933Y105 43,814 -6,268 -12.52 5,270 -0.02 0.5256
2026-02-17 2025-12-31 13F MERCK COM 58933Y105 0 -100.00 0
2026-02-17 2025-12-31 13F MERCK COM 58933Y105 50,082 1,510 3.11 5,272 29.32 0.5225
2025-10-10 2025-09-30 13F MERCK COM 58933Y105 48,572 -2,380 -4.67 4,077 1.07 0.5658
2025-07-14 2025-06-30 13F MERCK COM 58933Y105 50,952 6,300 14.11 4,033 0.65 0.5669
2025-04-14 2025-03-31 13F MERCK COM 58933Y105 44,652 -1,930 -4.14 4,008 -13.51 0.7107
2025-01-13 2024-12-31 13F MERCK COM 58933Y105 46,582 -3,150 -6.33 4,634 -17.96 0.8202
2024-10-10 2024-09-30 13F MERCK COM 58933Y105 49,732 2,590 5.49 5,648 -3.24 0.9738
2024-07-11 2024-06-30 13F MERCK COM 58933Y105 47,142 183 0.39 5,836 -5.81 1.1839
2024-04-12 2024-03-31 13F MERCK COM 58933Y105 46,959 1,489 3.27 6,196 24.99 1.2820
2024-01-16 2023-12-31 13F MERCK COM 58933Y105 45,470 -1,725 -3.66 4,957 2.04 1.1022
2023-10-27 2023-09-30 13F MERCK COM 58933Y105 47,195 -135 -0.29 4,859 -11.04 1.2202
2023-07-19 2023-06-30 13F MERCK COM 58933Y105 47,330 36 0.08 5,461 8.55 1.3094
2023-04-11 2023-03-31 13F MERCK COM 58933Y105 47,294 -6,371 -11.87 5,032 100,520.00 1.2628
2023-01-12 2022-12-31 13F MERCK COM 58933Y105 53,665 -7,840 -12.75 6 -99.91 1.4854
2022-10-13 2022-09-30 13F MERCK COM 58933Y105 61,505 -717 -1.15 5,296 -6.65 1.3736
2022-08-03 2022-06-30 13F MERCK COM 58933Y105 62,222 -12,872 -17.14 5,673 -7.92 1.4298
2022-04-12 2022-03-31 13F MERCK COM 58933Y105 75,094 10,467 16.20 6,161 24.39 0.9737
2022-01-18 2021-12-31 13F MERCK COM 58933Y105 64,627 717 1.12 4,953 3.19 0.9860
2021-10-13 2021-09-30 13F MERCK COM 58933Y105 63,910 1,295 2.07 4,800 -1.44 1.0542
2021-07-21 2021-06-30 13F MERCK COM 58933Y105 62,615 9,233 17.30 4,870 18.35 1.1522
2021-04-12 2021-03-31 13F MERCK & CO. COM 58933Y105 53,382 -5,885 -9.93 4,115 -15.14 1.4133
2021-01-28 2020-12-31 13F MERCK & CO. COM 58933Y105 59,267 5,698 10.64 4,849 9.14 1.6667
2020-10-08 2020-09-30 13F MERCK & CO. COM 58933Y105 53,569 3,905 7.86 4,443 15.70 1.8525
2020-07-13 2020-06-30 13F MERCK & CO. COM 58933Y105 49,664 -799 -1.58 3,840 -1.08 1.6990
2020-04-07 2020-03-31 13F MERCK & CO. COM 58933Y105 50,463 2,216 4.59 3,882 -11.53 1.9634
2020-01-13 2019-12-31 13F MERCK COM 58933Y105 48,247 -912 -1.86 4,388 6.04 1.7848
2019-10-09 2019-09-30 13F MERCK COM 58933Y105 49,159 234 0.48 4,138 0.88 1.7462
2019-07-23 2019-06-30 13F MERCK COM 58933Y105 48,925 -6,424 -11.61 4,102 -10.88 1.7480
2019-04-10 2019-03-31 13F MERCK COM 58933Y105 55,349 -17,153 -23.66 4,603 -16.91 1.9838
2019-01-09 2018-12-31 13F MERCK COM 58933Y105 72,502 -578 -0.79 5,540 6.85 2.6252
2018-10-10 2018-09-30 13F MERCK COM 58933Y105 73,080 1,279 1.78 5,185 18.98 2.0655
2018-07-12 2018-06-30 13F MERCK COM 58933Y105 71,801 7,795 12.18 4,358 25.01 1.8550
2018-05-10 2018-03-31 13F MERCK COM 58933Y105 64,006 8,566 15.45 3,486 11.73 1.4890
2018-01-17 2017-12-31 13F MERCK COM 58933Y105 55,440 2,411 4.55 3,120 -8.13 1.2466
2017-10-16 2017-09-30 13F MERCK COM 58933Y105 53,029 2,260 4.45 3,396 4.36 1.4320
2017-07-12 2017-06-30 13F MERCK COM 58933Y105 50,769 970 1.95 3,254 2.84 1.4455
2017-04-17 2017-03-31 13F MERCK COM 58933Y105 49,799 1,337 2.76 3,164 10.90 1.3992
2017-01-18 2016-12-31 13F MERCK COM 58933Y105 48,462 50 0.10 2,853 -5.56 1.2378
2016-10-12 2016-09-30 13F MERCK COM 58933Y105 48,412 -3,426 -6.61 3,021 1.17 1.3180
2016-07-08 2016-06-30 13F MERCK COM 58933Y105 51,838 -747 -1.42 2,986 7.33 1.2269
2016-04-08 2016-03-31 13F MERCK & CO INC COM 58933Y105 52,585 -1,937 -3.55 2,782 -3.40 1.1544
2016-01-08 2015-12-31 13F MERCK & CO INC COM 58933Y105 54,522 1,275 2.39 2,880 9.51 1.1172
2015-10-14 2015-09-30 13F MERCK & CO INC COM 58933Y105 53,247 2,734 5.41 2,630 -8.55 1.0099
2015-07-07 2015-06-30 13F MERCK & CO INC COM 58933Y105 50,513 1,106 2.24 2,876 1.27 1.0117
2015-04-16 2015-03-31 13F MERCK & CO INC COM 58933Y105 49,407 49,407 2,840 0.9730
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.