Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionKentucky Retirement Systems
Latest Disclosed Ownership241,239 shares
Latest Disclosed Value $ 12,074
Kentucky Retirement Systems reports 52.49% increase in ownership of MRK / Merck & Co., Inc.

On May 19, 2026 - Kentucky Retirement Systems filed a 13F-HR form disclosing ownership of 241,239 shares of Merck & Co., Inc. (MX:MRK) valued at $12,074 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 10, 2026 disclosing 158,196 shares of Merck & Co., Inc.. This represents a change in shares of 52.49% 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)
2026-05-19 2026-03-31 13F MERCK & CO INC COM 58933Y105 241,239 83,043 52.49 12 -99.93 0.8842
2026-02-10 2025-12-31 13F MERCK COM 58933Y105 158,196 0 0.00 16,652 25.41 0.4511
2025-11-13 2025-09-30 13F MERCK COM 58933Y105 158,196 -4,345 -2.67 13,277 3.19 0.3672
2025-08-20 2025-06-30 13F MERCK COM 58933Y105 162,541 -10,653 -6.15 12,867 -17.23 0.3764
2025-04-22 2025-03-31 13F MERCK COM 58933Y105 173,194 -995 -0.57 15,546 -10.29 0.4739
2025-02-03 2024-12-31 13F MERCK COM 58933Y105 174,189 -2,400 -1.36 17,328 -13.59 0.5108
2024-11-06 2024-09-30 13F MERCK COM 58933Y105 176,589 -14,274 -7.48 20,053 -15.13 0.5911
2024-08-12 2024-06-30 13F MERCK COM 58933Y105 190,863 -1,578 -0.82 23,629 -6.95 0.6845
2024-05-15 2024-03-31 13F MERCK COM 58933Y105 192,441 -10,308 -5.08 25,393 14.88 0.7587
2024-02-08 2023-12-31 13F MERCK COM 58933Y105 202,749 883 0.44 22,104 6.36 0.6900
2023-10-12 2023-09-30 13F MERCK COM 58933Y105 201,866 -2,150 -1.05 20,782 90,256.52 0.7222
2023-08-07 2023-06-30 13F MERCK COM 58933Y105 204,016 3,549 1.77 24 9.52 0.7880
2023-05-10 2023-03-31 13F MERCK COM 58933Y105 200,467 1,297 0.65 21 -4.55 0.7855
2023-02-06 2022-12-31 13F MERCK COM 58933Y105 199,170 870 0.44 22 -99.87 0.8715
2022-11-16 2022-09-30 13F MERCK COM 58933Y105 198,300 10,615 5.66 17,078 -0.19 0.7244
2022-08-08 2022-06-30 13F MERCK COM 58933Y105 187,685 26,680 16.57 17,111 29.53 0.7227
2022-05-09 2022-03-31 13F MERCK COM 58933Y105 161,005 10,347 6.87 13,210 14.41 0.5413
2022-02-04 2021-12-31 13F MERCK COM 58933Y105 150,658 3,474 2.36 11,546 4.44 0.4692
2021-11-17 2021-09-30 13F MERCK COM 58933Y105 147,184 -261 -0.18 11,055 -3.59 0.5201
2021-08-12 2021-06-30 13F MERCK COM 58933Y105 147,445 -1,776 -1.19 11,467 -0.31 0.5421
2021-05-14 2021-03-31 13F MERCK & CO. COM 58933Y105 149,221 -14,709 -8.97 11,503 -14.21 0.5624
2021-02-11 2020-12-31 13F MERCK & CO. COM 58933Y105 163,930 16,432 11.14 13,409 9.60 0.6920
2020-11-12 2020-09-30 13F MERCK & CO. COM 58933Y105 147,498 6,979 4.97 12,235 12.60 0.7549
2020-08-12 2020-06-30 13F MERCK & CO. COM 58933Y105 140,519 -33,361 -19.19 10,866 -18.78 0.7625
2020-05-01 2020-03-31 13F MERCK & CO. COM 58933Y105 173,880 42,900 32.75 13,378 12.30 0.9145
2020-02-18 2019-12-31 13F MERCK COM 58933Y105 130,980 -218 -0.17 11,913 7.87 0.8672
2019-11-05 2019-09-30 13F MERCK COM 58933Y105 131,198 11,297 9.42 11,044 9.85 0.8771
2019-08-07 2019-06-30 13F/A-1 MERCK COM 58933Y105 119,901 7,049 6.25 10,054 7.12 0.8865
2019-08-07 2019-06-30 13F MERCK COM 58933Y105 119,901 7,049 10,054
2019-05-22 2019-03-31 13F MERCK COM 58933Y105 112,852 -260 -0.23 9,386 8.60 0.9084
2019-02-25 2018-12-31 13F MERCK COM 58933Y105 113,112 -143 -0.13 8,643 7.58 0.9470
2018-11-19 2018-09-30 13F/A-1 MERCK COM 58933Y105 113,255 -968 -0.85 8,034 15.88 0.7679
2018-11-16 2018-09-30 13F MERCK & CO INC COM 58933Y105 241,239 127,016 12,074
2018-08-13 2018-06-30 13F MERCK COM 58933Y105 114,223 -26,486 -18.82 6,933 -9.54 0.7095
2018-05-07 2018-03-31 13F MERCK COM 58933Y105 140,709 -27,960 -16.58 7,664 -19.25 0.6531
2018-02-13 2017-12-31 13F MERCK COM 58933Y105 168,669 726 0.43 9,491 -11.74 0.6759
2017-11-08 2017-09-30 13F MERCK COM 58933Y105 167,943 -7,393 -4.22 10,753 -4.31 0.8119
2017-08-18 2017-06-30 13F MERCK COM 58933Y105 175,336 -691 -0.39 11,237 0.46 0.8445
2017-05-24 2017-03-31 13F MERCK COM 58933Y105 176,027 -24,043 -12.02 11,185 -5.03 0.8612
2017-02-24 2016-12-31 13F MERCK COM 58933Y105 200,070 -11,270 -5.33 11,778 -10.71 0.8427
2016-11-30 2016-09-30 13F MERCK COM 58933Y105 211,340 -24,047 -10.22 13,190 -2.74 0.8778
2016-09-12 2016-06-30 13F MERCK COM 58933Y105 235,387 -19,579 -7.68 13,561 0.53 0.8773
2016-06-09 2016-03-31 13F MERCK & CO INC COM 58933Y105 254,966 42,784 20.16 13,490 20.37 0.8187
2016-02-22 2015-12-31 13F MERCK & CO INC COM 58933Y105 212,182 18,914 9.79 11,207 17.40 0.8251
2015-11-18 2015-09-30 13F MERCK & CO INC COM 58933Y105 193,268 2,638 1.38 9,546 -12.04 0.8222
2015-08-26 2015-06-30 13F MERCK & CO INC COM 58933Y105 190,630 -402 -0.21 10,853 -1.17 0.8830
2015-05-29 2015-03-31 13F MERCK & CO INC COM 58933Y105 191,032 -20,890 -9.86 10,981 -8.76 0.8914
2015-03-04 2014-12-31 13F MERCK & CO INC COM 58933Y105 211,922 -12,493 -5.57 12,035 -9.53 0.8875
2014-12-12 2014-09-30 13F MERCK & CO INC COM 58933Y105 224,415 -19,339 -7.93 13,303 -3.87 0.9762
2014-05-22 2014-03-31 13F MERCK & CO INC COM 58933Y105 243,754 2,515 1.04 13,838 14.61 0.9995
2014-02-13 2013-12-31 13F MERCK & CO INC COM 58933Y105 241,239 -1,833 -0.75 12,074 4.33 0.8842
2013-11-15 2013-09-30 13F MERCK & CO INC COM 58933Y105 243,072 243,072 11,573 0.9321
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.