Merck & Co., Inc.
MX ˙ BMV ˙ US58933Y1055
SecurityMX:MRK / Merck & Co., Inc.
InstitutionCandriam Luxembourg S.C.A.
Latest Disclosed Ownership1,322,654 shares
Latest Disclosed Value $ 159,102,050
Candriam Luxembourg S.C.A. reports 3.68% increase in ownership of MRK / Merck & Co., Inc.

On April 30, 2026 - Candriam Luxembourg S.C.A. filed a 13F-HR form disclosing ownership of 1,322,654 shares of Merck & Co., Inc. (MX:MRK) valued at $159,102,050 USD as of March 31, 2026. The entity filed a previous 13F-HR/A on April 30, 2026 disclosing 1,275,687 shares of Merck & Co., Inc.. This represents a change in shares of 3.68% 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)
2026-04-30 2026-03-31 13F MERCK COM 58933Y105 1,322,654 46,967 3.68 159,102 18.48 0.8265
2026-04-30 2025-12-31 13F/A-1 MERCK COM 58933Y105 1,275,687 -143,474 -10.11 134,285 12.74 0.6696
2026-02-13 2025-12-31 13F MERCK COM 58933Y105 1,276,600 -142,561 134,381 0.6691
2025-11-06 2025-09-30 13F MERCK COM 58933Y105 1,419,161 -234,938 -14.20 119,110 -9.04 0.6236
2025-08-08 2025-06-30 13F MERCK COM 58933Y105 1,654,099 -494,389 -23.01 130,944 -32.10 0.7550
2025-05-14 2025-03-31 13F MERCK COM 58933Y105 2,148,488 -68,935 -3.11 192,848 -12.58 1.2078
2025-02-07 2024-12-31 13F MERCK COM 58933Y105 2,217,423 -248,291 -10.07 220,589 -21.22 1.2703
2024-11-13 2024-09-30 13F MERCK COM 58933Y105 2,465,714 85,249 3.58 279,994 -4.99 1.6090
2024-08-05 2024-06-30 13F MERCK COM 58933Y105 2,380,465 -92,865 -3.75 294,688 -9.70 1.7862
2024-05-06 2024-03-31 13F MERCK COM 58933Y105 2,473,330 -556,959 -18.38 326,356 -1.22 2.0871
2024-02-14 2023-12-31 13F MERCK COM 58933Y105 3,030,289 -305,310 -9.15 330,377 -3.79 2.2803
2023-11-13 2023-09-30 13F MERCK COM 58933Y105 3,335,599 209,628 6.71 343,400 -4.80 2.4337
2023-08-08 2023-06-30 13F MERCK COM 58933Y105 3,125,971 -344,091 -9.92 360,706 6.15 2.6068
2023-05-12 2023-03-31 13F MERCK COM 58933Y105 3,470,062 264,370 8.25 339,805 -4.46 2.3569
2023-02-13 2022-12-31 13F MERCK COM 58933Y105 3,205,692 -272,866 -7.84 355,655 18.71 2.3992
2022-11-10 2022-09-30 13F MERCK COM 58933Y105 3,478,558 -3,480 -0.10 299,589 -5.62 2.1106
2022-08-03 2022-06-30 13F MERCK COM 58933Y105 3,482,038 -58,091 -1.64 317,442 9.29 2.6140
2022-05-13 2022-03-31 13F MERCK COM 58933Y105 3,540,129 887,274 33.45 290,455 42.86 1.9764
2022-02-10 2021-12-31 13F MERCK COM 58933Y105 2,652,855 -1,010,324 -27.58 203,315 -26.10 1.2976
2021-11-09 2021-09-30 13F MERCK COM 58933Y105 3,663,179 -655,128 -15.17 275,129 -18.08 1.8703
2021-07-20 2021-06-30 13F MERCK COM 58933Y105 4,318,307 661,686 18.10 335,835 16.89 2.2988
2021-04-29 2021-03-31 13F MERCK & CO. COM 58933Y105 3,656,621 4 0.00 287,308 -3.95 2.3914
2021-01-22 2020-12-31 13F MERCK & CO. COM 58933Y105 3,656,617 722,415 24.62 299,115 22.90 2.3670
2020-10-19 2020-09-30 13F MERCK & CO. COM 58933Y105 2,934,202 895,634 43.93 243,382 54.38 2.2863
2020-07-23 2020-06-30 13F MERCK & CO. COM 58933Y105 2,038,568 644,925 46.28 157,649 27.23 1.6641
2020-05-26 2020-03-31 13F MERCK & CO. COM 58933Y105 1,393,643 129 0.01 123,907 -2.24 1.3733
2020-02-05 2019-12-31 13F/A-1 MERCK COM 58933Y105 1,393,514 -178,360 -11.35 126,742 -4.22 1.3584
2020-01-21 2019-12-31 13F MERCK COM 58933Y105 1,393,514 -178,377 127 1,362,076.3621
2020-02-05 2019-09-30 13F/A-1 MERCK COM 58933Y105 1,571,874 -105,063 -6.27 132,320 -6.21 1.7535
2019-10-21 2019-09-30 13F MERCK COM 58933Y105 1,571,891 -105,046 133 1,671,484.2277
2019-08-01 2019-06-30 13F MERCK COM 58933Y105 1,676,937 119,252 7.66 141,083 8.20 1.7596
2019-05-02 2019-03-31 13F MERCK COM 58933Y105 1,557,685 557,628 55.76 130,390 70.64 1.6681
2019-02-14 2018-12-31 13F MERCK COM 58933Y105 1,000,057 -241,813 -19.47 76,411 -13.27 1.1742
2018-11-07 2018-09-30 13F MERCK COM 58933Y105 1,241,870 817,664 192.75 88,098 242.13 1.1712
2018-08-14 2018-06-30 13F MERCK COM 58933Y105 424,206 -163,231 -27.79 25,750 -19.52 0.4075
2018-05-09 2018-03-31 13F MERCK COM 58933Y105 587,437 57,468 10.84 31,997 7.29 0.5457
2018-02-07 2017-12-31 13F MERCK COM 58933Y105 529,969 -62,726 -10.58 29,824 -21.41 0.5160
2017-11-03 2017-09-30 13F MERCK COM 58933Y105 592,695 -14,215 -2.34 37,950 -2.44 0.6630
2017-07-31 2017-06-30 13F MERCK COM 58933Y105 606,910 295,293 94.76 38,899 96.45 0.7310
2017-04-21 2017-03-31 13F MERCK COM 58933Y105 311,617 -13,993 -4.30 19,801 3.30 0.3833
2017-02-01 2016-12-31 13F MERCK COM 58933Y105 325,610 -162,788 -33.33 19,168 -37.11 0.4398
2016-11-15 2016-09-30 13F MERCK COM 58933Y105 488,398 91,638 23.10 30,481 33.35 0.7331
2016-07-26 2016-06-30 13F MERCK COM 58933Y105 396,760 -193,206 -32.75 22,858 -26.38 0.5943
2016-04-27 2016-03-31 13F MERCK & CO INC COM 58933Y105 589,966 35,049 6.32 31,047 5.93 0.7764
2016-01-25 2015-12-31 13F MERCK & CO INC COM 58933Y105 554,917 -161,975 -22.59 29,309 -17.23 0.7841
2015-10-19 2015-09-30 13F MERCK & CO INC COM 58933Y105 716,892 -79,505 -9.98 35,409 -21.90 0.8694
2015-07-29 2015-06-30 13F MERCK & CO INC COM 58933Y105 796,397 -64,933 -7.54 45,339 -8.44 0.9436
2015-05-28 2015-03-31 13F/A-1 MERCK & CO INC COM 58933Y105 861,330 32,648 3.94 49,521 5.23 0.9976
2015-04-27 2015-03-31 13F MERCK & CO INC COM 58933Y105 865,246 49,734
2015-05-28 2014-12-31 13F/A-1 MERCK & CO INC COM 58933Y105 828,682 828,682 47,061 0.9838
2015-03-26 2014-12-31 13F MERCK & CO INC COM 58933Y105 904,787 904,787 51,383 1.0400
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.