Regeneron Pharmaceuticals, Inc.
US ˙ NasdaqGS ˙ US75886F1075

SecurityREGN / Regeneron Pharmaceuticals, Inc.
InstitutionBrown Advisory Inc
Latest Disclosed Ownership3,264 shares
Latest Disclosed Value $ 2,521,897
Brown Advisory Inc reports 5.39% decrease in ownership of REGN / Regeneron Pharmaceuticals, Inc.

On May 15, 2026 - Brown Advisory Inc filed a 13F-HR form disclosing ownership of 3,264 shares of Regeneron Pharmaceuticals, Inc. (US:REGN) valued at $2,521,897 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 3,450 shares of Regeneron Pharmaceuticals, Inc.. This represents a change in shares of -5.39% during the quarter. The current value of the position is $2,020,253 USD.

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)
2026-05-15 2026-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 3,264 -186 -5.39 2,522 -5.30 0.0018
2026-02-13 2025-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 3,450 109 3.26 2,663 41.75 0.0037
2025-11-14 2025-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 3,341 -439 -11.61 1,879 -5.34 0.0024
2025-08-13 2025-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 3,780 -489 -11.45 1,984 -26.71 0.0026
2025-04-30 2025-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 4,269 -247 -5.47 2,708 -15.83 0.0039
2025-02-14 2024-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 4,516 -109 -2.36 3,217 -33.84 0.0041
2024-11-13 2024-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 4,625 -37 -0.79 4,862 -0.78 0.0061
2024-08-14 2024-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 4,662 13 0.28 4,900 9.50 0.0064
2024-04-24 2024-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 4,649 639 15.94 4,475 27.07 0.0060
2024-02-08 2023-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 4,010 -69 -1.69 3,522 4.92 0.0050
2023-10-25 2023-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 4,079 -1 -0.02 3,357 14.50 0.0055
2023-07-31 2023-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 4,080 -233 -5.40 2,932 -17.27 0.0046
2023-05-08 2023-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 4,313 -251 -5.50 3,544 7.62 0.0060
2023-02-13 2022-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 4,564 -73 -1.57 3,293 3.04 0.0061
2022-11-14 2022-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 4,637 1,675 56.55 3,195 82.47 0.0062
2022-11-14 2022-06-30 13F/A-2 REGENERON PHARMACEUTICALS COM 75886F107 2,962 383 14.85 1,751 -2.78 0.0033
2022-09-13 2022-06-30 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 3,397 767 2,008 0.0035
2022-08-02 2022-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 3,162 383 1,892 0.0030
2022-11-14 2022-03-31 13F/A-2 REGENERON PHARMACEUTICALS COM 75886F107 2,579 -26 -1.00 1,801 9.48 0.0027
2022-09-13 2022-03-31 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 2,630 25 1,837 0.0026
2022-05-09 2022-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 2,779 174 1,903 0.0026
2022-01-27 2021-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 2,605 198 8.23 1,645 12.90 0.0020
2021-11-12 2021-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 2,407 3 0.12 1,457 8.49 0.0022
2021-07-29 2021-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 2,404 114 4.98 1,343 23.89 0.0020
2021-05-14 2021-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 2,290 9 0.39 1,084 -1.63 0.0019
2021-02-12 2020-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 2,281 -450 -16.48 1,102 -27.93 0.0020
2020-11-16 2020-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 2,731 4 0.15 1,529 -10.11 0.0032
2020-08-14 2020-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 2,727 34 1.26 1,701 29.45 0.0040
2020-05-15 2020-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 2,693 20 0.75 1,314 30.88 0.0040
2020-02-14 2019-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 2,673 127 4.99 1,004 42.01 0.0025
2019-11-14 2019-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 2,546 1,246 95.85 707 73.71 0.0020
2019-08-12 2019-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 1,300 -790 -37.80 407 -52.62 0.0012
2019-05-15 2019-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 2,090 168 8.74 859 19.80 0.0024
2019-02-13 2018-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 1,922 -1,238 -39.18 717 -43.81 0.0024
2018-11-13 2018-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 3,160 -8,663 -73.27 1,276 -68.72 0.0036
2018-08-10 2018-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 11,823 8,898 304.21 4,079 305.06 0.0125
2018-06-28 2018-03-31 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 2,925 90 3.17 1,007 -5.45 0.0033
2018-05-14 2018-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 2,414 -421 831
2018-02-12 2017-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 2,835 110 4.04 1,065 -12.56 0.0034
2017-11-13 2017-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 2,725 -21 -0.76 1,218 -9.64 0.0040
2017-08-14 2017-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 2,746 -146 -5.05 1,348 20.25 0.0041
2017-05-15 2017-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 2,892 252 9.55 1,121 15.69 0.0038
2017-02-13 2016-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 2,640 678 34.56 969 22.97 0.0035
2016-11-14 2016-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 1,962 -1,540 -43.97 788 -35.57 0.0027
2016-08-09 2016-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 3,502 1,651 89.20 1,223 83.36 0.0043
2016-05-13 2016-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 1,851 -69 -3.59 667 -35.99 0.0023
2016-02-08 2015-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 1,920 58 3.11 1,042 20.32 0.0035
2015-11-13 2015-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 1,862 1,132 155.07 866 132.80 0.0031
2015-08-11 2015-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 730 -1,340 -64.73 372 -60.21 0.0012
2015-05-14 2015-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 2,070 -169 -7.55 935 1.74 0.0030
2015-02-13 2014-12-31 13F/A-1 REGENERON PHARMACEUTICALS COM 75886F107 2,239 -799 -26.30 919 -16.07 0.0029
2015-02-09 2014-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 3,239 1,242
2014-11-10 2014-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 3,038 104 3.54 1,095 31.93 0.0035
2014-08-08 2014-06-30 13F REGENERON PHARMACEUTICALS COM 75886F107 2,934 35 1.21 830 -4.71 0.0026
2014-05-13 2014-03-31 13F REGENERON PHARMACEUTICALS COM 75886F107 2,899 16 0.55 871 9.70 0.0028
2014-02-11 2013-12-31 13F REGENERON PHARMACEUTICALS COM 75886F107 2,883 350 13.82 794 0.13 0.0026
2013-11-08 2013-09-30 13F REGENERON PHARMACEUTICALS COM 75886F107 2,533 2,533 793 0.0028
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.