Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionArizona State Retirement System
Latest Disclosed Ownership679,746 shares
Latest Disclosed Value $ 81,766,646
Arizona State Retirement System reports 3.21% decrease in ownership of MRK / Merck & Co., Inc.

On May 1, 2026 - Arizona State Retirement System filed a 13F-HR form disclosing ownership of 679,746 shares of Merck & Co., Inc. (MX:MRK) valued at $81,766,646 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 28, 2026 disclosing 702,282 shares of Merck & Co., Inc.. This represents a change in shares of -3.21% 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)
2026-05-01 2026-03-31 13F MERCK COM 58933Y105 679,746 -22,536 -3.21 81,767 10.61 0.4782
2026-01-28 2025-12-31 13F MERCK COM 58933Y105 702,282 -31,306 -4.27 73,922 20.06 0.4021
2025-11-03 2025-09-30 13F MERCK COM 58933Y105 733,588 -2,061 -0.28 61,570 5.73 0.3281
2025-08-13 2025-06-30 13F MERCK COM 58933Y105 735,649 -6,731 -0.91 58,234 -12.61 0.3355
2025-05-01 2025-03-31 13F MERCK COM 58933Y105 742,380 6,713 0.91 66,636 -8.95 0.4242
2025-02-06 2024-12-31 13F MERCK COM 58933Y105 735,667 9,450 1.30 73,184 -11.26 0.4473
2024-11-12 2024-09-30 13F MERCK COM 58933Y105 726,217 -8,011 -1.09 82,469 -9.27 0.5201
2024-08-05 2024-06-30 13F MERCK COM 58933Y105 734,228 7,048 0.97 90,897 -5.27 0.6068
2024-05-07 2024-03-31 13F MERCK COM 58933Y105 727,180 13,264 1.86 95,951 23.28 0.6638
2024-01-24 2023-12-31 13F MERCK COM 58933Y105 713,916 -4,311 -0.60 77,831 5.26 0.5907
2023-11-07 2023-09-30 13F MERCK COM 58933Y105 718,227 -7,162 -0.99 73,941 -11.66 0.6282
2023-08-01 2023-06-30 13F MERCK COM 58933Y105 725,389 33,118 4.78 83,703 13.65 0.6794
2023-04-27 2023-03-31 13F MERCK COM 58933Y105 692,271 2,024 0.29 73,651 -3.83 0.6609
2023-02-08 2022-12-31 13F MERCK COM 58933Y105 690,247 2,852 0.41 76,583 29.37 0.7395
2022-11-07 2022-09-30 13F MERCK COM 58933Y105 687,395 -6,078 -0.88 59,198 -6.37 0.6123
2022-07-28 2022-06-30 13F MERCK COM 58933Y105 693,473 357 0.05 63,224 11.17 0.6136
2022-05-04 2022-03-31 13F MERCK COM 58933Y105 693,116 -178 -0.03 56,870 7.03 0.4581
2022-02-04 2021-12-31 13F MERCK COM 58933Y105 693,294 -12,801 -1.81 53,134 0.19 0.4048
2021-11-12 2021-09-30 13F MERCK COM 58933Y105 706,095 -2,837 -0.40 53,035 -3.81 0.4328
2021-08-02 2021-06-30 13F MERCK COM 58933Y105 708,932 -4,042 -0.57 55,134 0.31 0.4483
2021-05-06 2021-03-31 13F MERCK COM 58933Y105 712,974 -16,811 -2.30 54,963 -7.93 0.4801
2021-01-28 2020-12-31 13F MERCK COM 58933Y105 729,785 -37,849 -4.93 59,696 -6.25 0.5414
2020-11-05 2020-09-30 13F MERCK COM 58933Y105 767,634 171,848 28.84 63,675 38.21 0.6330
2020-08-04 2020-06-30 13F MERCK COM 58933Y105 595,786 80,580 15.64 46,072 16.23 0.6499
2020-05-05 2020-03-31 13F MERCK COM 58933Y105 515,206 -7,474 -1.43 39,640 -16.61 0.6814
2020-01-27 2019-12-31 13F MERCK COM 58933Y105 522,680 6,852 1.33 47,538 9.48 0.5724
2019-10-31 2019-09-30 13F MERCK COM 58933Y105 515,828 -11,982 -2.27 43,422 -1.89 0.5298
2019-07-25 2019-06-30 13F MERCK COM 58933Y105 527,810 -18,390 -3.37 44,257 -2.58 0.5124
2019-04-29 2019-03-31 13F MERCK COM 58933Y105 546,200 -52,385 -8.75 45,427 -0.68 0.5402
2019-01-28 2018-12-31 13F MERCK COM 58933Y105 598,585 -119,882 -16.69 45,738 -10.26 0.5885
2018-10-29 2018-09-30 13F MERCK COM 58933Y105 718,467 -2,228 -0.31 50,968 16.51 0.4810
2018-08-07 2018-06-30 13F MERCK COM 58933Y105 720,695 11,874 1.68 43,746 13.31 0.4400
2018-05-14 2018-03-31 13F MERCK COM 58933Y105 708,821 -20,600 -2.82 38,609 -5.93 0.3897
2018-02-09 2017-12-31 13F MERCK COM 58933Y105 729,421 -17,635 -2.36 41,045 -14.19 0.3999
2017-11-14 2017-09-30 13F MERCK COM 58933Y105 747,056 -225,961 -23.22 47,834 -23.30 0.5716
2017-08-02 2017-06-30 13F MERCK COM 58933Y105 973,017 -26,265 -2.63 62,361 -1.78 0.8640
2017-05-10 2017-03-31 13F MERCK COM 58933Y105 999,282 -2,100 -0.21 63,494 7.71 0.8918
2017-02-10 2016-12-31 13F MERCK COM 58933Y105 1,001,382 3,900 0.39 58,951 -5.30 0.8676
2016-11-01 2016-09-30 13F MERCK + COM 58933Y105 997,482 -70,700 -6.62 62,253 1.16 0.9452
2016-08-15 2016-06-30 13F MERCK + COM 58933Y105 1,068,182 -93,600 -8.06 61,538 0.11 0.8639
2016-05-16 2016-03-31 13F MERCK + COM 58933Y105 1,161,782 -6,100 -0.52 61,470 -0.35 0.8000
2016-02-12 2015-12-31 13F MERCK + COM 58933Y105 1,167,882 -71,800 -5.79 61,688 0.75 0.8210
2015-11-20 2015-09-30 13F MERCK + COM 58933Y105 1,239,682 -80,181 -6.07 61,228 -18.31 0.8588
2015-02-11 2014-12-31 13F MERCK + COM 58933Y105 1,319,863 11,400 0.87 74,955 -3.36 0.8830
2014-11-21 2014-09-30 13F MERCK + COM 58933Y105 1,308,463 -48,600 -3.58 77,565 -1.20 0.9621
2014-08-07 2014-06-30 13F MERCK + COM 58933Y105 1,357,063 -9,800 -0.72 78,506 1.17 0.9492
2014-05-19 2014-03-31 13F MERCK + COM 58933Y105 1,366,863 -34,900 -2.49 77,596 10.60 0.9827
2014-02-05 2013-12-31 13F MERCK + COM 58933Y105 1,401,763 -63,400 -4.33 70,158 0.58 0.8630
2013-11-01 2013-09-30 13F MERCK + COM 58933Y105 1,465,163 -43,900 -2.91 69,756 -0.48 0.8934
2013-09-17 2013-06-30 13F MERCK + COM 58933Y105 1,509,063 42,700 2.91 70,095 8.08 0.9557
2013-09-17 2013-03-31 13F MERCK + COM 58933Y105 1,466,363 1,466,363 64,857 0.9292
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.