Regeneron Pharmaceuticals, Inc.
MX ˙ BMV ˙ US75886F1075
SecurityMX:REGN / Regeneron Pharmaceuticals, Inc.
InstitutionRobeco Institutional Asset Management B.V.
Latest Disclosed Ownership348,787 shares
Latest Disclosed Value $ 269,486,789
Robeco Institutional Asset Management B.V. reports 33.20% increase in ownership of REGN / Regeneron Pharmaceuticals, Inc.

On April 21, 2026 - Robeco Institutional Asset Management B.V. filed a 13F-HR form disclosing ownership of 348,787 shares of Regeneron Pharmaceuticals, Inc. (MX:REGN) valued at $269,486,789 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 23, 2026 disclosing 261,850 shares of Regeneron Pharmaceuticals, Inc.. This represents a change in shares of 33.20% 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)
2026-04-21 2026-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 348,787 86,937 33.20 269,487 33.33 0.3841
2026-01-23 2025-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 261,850 140,966 116.61 202,114 197.36 0.2878
2025-10-22 2025-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 120,884 73,176 153.38 67,969 171.38 0.0985
2025-07-18 2025-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 47,708 -64,787 -57.59 25,047 -64.90 0.0405
2025-04-23 2025-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 112,495 -16,813 -13.00 71,348 -22.54 0.1386
2025-01-23 2024-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 129,308 1,130 0.88 92,110 -31.64 0.1746
2024-10-29 2024-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 128,178 1,243 0.98 134,746 1.00 0.2677
2024-07-23 2024-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 126,935 10,568 9.08 133,412 19.12 0.2871
2024-04-24 2024-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 116,367 -3,924 -3.26 112,002 6.01 0.2434
2024-02-14 2023-12-31 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 120,291 4,758 4.12 105,650 11.12 0.2561
2024-02-08 2023-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 64,232 -51,301 120 0.0225
2023-10-24 2023-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 115,533 -7,312 -5.95 95,079 7.72 0.2541
2023-07-24 2023-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 122,845 -578 -0.47 88,269 -12.96 0.2314
2023-05-04 2023-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 123,423 375 0.30 101,413 14.23 0.2765
2023-02-07 2022-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 123,048 19,598 18.94 88,778 24.57 0.2558
2022-12-01 2022-09-30 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 103,450 20,690 25.00 71,264 45.68 0.2303
2022-10-27 2022-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 103,450 20,690 71,264 0.2272
2022-12-01 2022-06-30 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 82,760 14,984 22.11 48,919 3.35 0.1520
2022-07-27 2022-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 82,760 14,984 48,919 0.1499
2022-12-01 2022-03-31 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 67,776 17,331 34.36 47,335 48.59 0.1115
2022-04-26 2022-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 67,776 17,331 47,335 0.1102
2022-12-01 2021-12-31 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 50,445 -8,193 -13.97 31,856 -10.23 0.0678
2022-01-31 2021-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 50,445 -8,193 31,856 0.0670
2022-12-01 2021-09-30 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 58,638 21,394 57.44 35,486 70.59 0.0787
2021-10-20 2021-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 58,638 21,394 35,486 0.0777
2022-12-01 2021-06-30 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 37,244 -75,370 -66.93 20,802 -60.96 0.0461
2021-07-28 2021-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 37,244 -75,370 20,802 0.0455
2022-12-01 2021-03-31 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 112,614 -45,859 -28.94 53,280 -30.40 0.1313
2021-04-23 2021-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 112,614 -45,859 53,280 0.1295
2022-12-01 2020-12-31 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 158,473 -15,697 -9.01 76,557 -21.48 0.2012
2021-01-28 2020-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 158,473 -15,697 76,557 0.1987
2021-01-19 2020-09-30 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 174,170 19,050 12.28 97,495 0.78 0.3013
2020-10-29 2020-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 174,170 19,050 97,495 301,096.2907
2021-01-19 2020-06-30 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 155,120 119,756 338.64 96,742 460.21 0.3285
2020-07-20 2020-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 155,120 119,756 96,742 328,262.8617
2021-01-19 2020-03-31 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 35,364 22,290 170.49 17,269 251.78 0.0693
2020-04-30 2020-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 35,364 22,290 17,269 69,218.0465
2021-01-19 2019-12-31 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 13,074 -5,122 -28.15 4,909 -2.75 0.0157
2020-02-06 2019-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 13,074 -5,122 4,909 15,701.0590
2021-01-19 2019-09-30 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 18,196 -1,150 -5.94 5,048 -16.66 0.0178
2019-10-17 2019-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 18,196 -1,150 5,048 17,796.2760
2021-01-19 2019-06-30 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 19,346 -1,955 -9.18 6,057 -30.76 0.0214
2019-07-19 2019-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 19,346 -1,955 6,057 21,358.5663
2021-01-19 2019-03-31 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 21,301 7,931 59.32 8,748 75.52 0.0322
2019-05-02 2019-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 21,301 7,931 8,748 32,119.5440
2021-01-19 2018-12-31 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 13,370 7,806 140.29 4,984 121.81 0.0224
2019-02-08 2018-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 13,370 7,806 4,984 22,340.5330
2021-01-19 2018-09-30 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 5,564 1,000 21.91 2,247 42.67 0.0089
2018-10-25 2018-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 5,564 1,000 2,247
2021-01-19 2018-06-30 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 4,564 -678 -12.93 1,575 -12.79 0.0072
2018-08-03 2018-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 4,564 -678 1,575
2021-01-19 2018-03-31 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 5,242 4,204 405.01 1,806 361.89 0.0085
2018-05-07 2018-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 5,242 4,204 1,806 8,445.8172
2021-01-19 2017-12-31 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 1,038 0 0.00 391 -15.55 0.0020
2018-01-25 2017-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 1,038 0 391
2021-01-19 2017-09-30 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 1,038 12 1.17 463 -8.13 0.0029
2017-10-17 2017-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 1,038 12 463 2,868.4474
2021-01-19 2017-06-30 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 1,026 0 0.00 504 26.63 0.0032
2017-08-07 2017-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 1,026 0 504 3,281.4459
2021-01-19 2017-03-31 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 1,026 -55 -5.09 398 0.51 0.0027
2017-05-15 2017-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 1,026 -55 398 2,643.4920
2017-02-09 2016-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 1,081 -2,302 -68.05 396 -70.88 0.0031
2016-11-07 2016-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 3,383 -2,156 -38.92 1,360 -29.68 0.0101
2016-07-22 2016-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 5,539 0 0.00 1,934 -3.11 0.0147
2016-05-16 2016-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 5,539 -1,262 -18.56 1,996 -45.95 0.0160
2016-02-08 2015-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 6,801 1,889 38.46 3,693 61.62 0.0316
2015-11-12 2015-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 4,912 1,865 61.21 2,285 47.04 0.0174
2015-08-17 2015-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 3,047 650 27.12 1,554 43.62 0.0118
2015-04-24 2015-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 2,397 334 16.19 1,082 27.90 0.0081
2015-02-12 2014-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 2,063 2,063 0.00 846 0.0061
2014-11-10 2014-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 0 -1,266 -100.00 0 -100.00
2014-08-13 2014-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 1,266 650 105.52 358 93.51 0.0026
2014-05-07 2014-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 616 161 35.38 185 48.00 0.0014
2014-02-04 2013-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 455 0 0.00 125 -11.97 0.0010
2013-11-12 2013-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 455 0 0.00 142 39.22 0.0014
2013-08-27 2013-06-30 13F Regeneron Pharmaceuticals COM 75886F107 455 455 102 0.0010
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.