REGENERON PHARMACEUTICALS (REGN) Institutional Selling Activity
Several institutional investors tracked by InsiderSet reduced exposure to REGENERON PHARMACEUTICALS (REGN) during the quarter ended June 30, 2026 based on sequential SEC Form 13F filings.
The largest disclosed institutional seller of REGN during the latest reporting period reduced its reported position by approximately $1.08B based on quarter-end filing values.
Institutional selling activity may reflect profit-taking, sector rotation, portfolio rebalancing, or changing conviction levels among major investment firms. InsiderSet tracks quarter-over-quarter holding reductions, full exits, estimated value changes, and historical selling activity using publicly disclosed SEC filing data.
The investors covered on this page collectively reduced approximately $1.78B in reported REGN exposure during the latest filing period, although many institutional holders continue to maintain significant long-term ownership positions in REGENERON PHARMACEUTICALS.
| Portfolio quarter | Name | Type | Quantity | Remaining | Reported stock balance |
|---|---|---|---|---|---|
| Q2 2026 | Sound Shore Management | Sell | -23,966 | 126,994 | $79,185,839 |
| Q2 2026 | Parnassus Endeavor Fund | Sell | -2,117 | 95,378 | $59,471,998 |
| Q2 2026 | Sequoia Financial Advisors | Sell | -502 | 2,687 | $1,675,761 |
| Q1 2026 | Dodge & Cox Stock Fund | Sell | -138,120 | 4,458,238 | $3,444,613,008 |
| Q1 2026 | Longleaf Partners | Sell | -35,130 | 130,662 | $100,954,687 |
| Q1 2026 | Sound Shore Management | Sell | -24,927 | 150,960 | $116,637,734 |
| Q4 2025 | Renaissance Technologies LLC | Sell | -266,080 | 9,082 | $7,010,123 |
| Q4 2025 | ARK Invest | Sell | -12,032 | 110 | $84,651 |
| Q4 2025 | Parnassus Endeavor Fund | Sell | -4,478 | 96,545 | $74,520,189 |
| Q3 2025 | Longleaf Partners | Sell | -15,974 | 144,607 | $81,308,178 |
| Q3 2025 | ARK Invest | Sell | -464 | 12,142 | $6,827,330 |
| Q3 2025 | Parnassus Endeavor Fund | Sell | -61 | 101,023 | $56,802,202 |
| Q2 2025 | Parnassus Endeavor Fund | Sell | -43,916 | 101,084 | $53,069,100 |
| Q2 2025 | Renaissance Technologies LLC | Sell | -33,839 | 45,062 | $23,657,550 |
| Q2 2025 | ARK Invest | Sell | -1,088 | 12,606 | $6,618,213 |
| Q1 2025 | Renaissance Technologies LLC | Sell | -168,842 | 78,901 | $50,041,381 |
| Q1 2025 | Sequoia Financial Advisors | Sell | -134 | 1,615 | $1,024,475 |
| Q4 2024 | ARK Invest | Sell | -1,959 | 13,192 | $9,397,287 |
| Q3 2024 | Viking Global Investors | Sell | -1,030,812 | 49,870 | $52,425,339 |
| Q3 2024 | Dodge & Cox Stock Fund | Sell | -3,751 | 2,311,935 | $2,430,398,549 |
| Q3 2024 | ARK Invest | Sell | -714 | 15,151 | $15,927,779 |
| Q2 2024 | Dodge & Cox Stock Fund | Sell | -44,178 | 2,315,686 | $2,433,855,457 |
| Q2 2024 | ARK Invest | Sell | -2,348 | 15,865 | $16,674,439 |
| Q1 2024 | Renaissance Technologies LLC | Sell | -77,700 | 165,362 | $159,159 |
| Q1 2024 | ARK Invest | Sell | -9,518 | 18,213 | $17,529,940 |
| Q1 2024 | Dodge & Cox Stock Fund | Sell | -7,816 | 2,359,864 | $2,271,345,501 |
| Q1 2024 | Sequoia Financial Advisors | Sell | -650 | 1,449 | $1,394,617 |
| Q4 2023 | Dodge & Cox Stock Fund | Sell | -5,318 | 2,367,680 | $2,079,509,667 |
| Q4 2023 | ARK Invest | Sell | -9 | 27,731 | $24,355,445 |
| Q3 2023 | Dodge & Cox Stock Fund | Sell | -21,357 | 2,372,998 | $1,952,882,434 |
Frequently asked questions about REGN activity
Which institutional owners are buying REGN?
Institutional owners buying REGN include investors who have either initiated new positions or increased their existing holdings based on recent SEC 13F filings. The activity table above highlights which funds added shares in the latest reporting periods and how their positions changed over time.
What does "buy" mean in REGN activity?
"Buy" means an investor increased their reported position in REGN compared to the prior reporting period. This reflects growing exposure to REGENERON PHARMACEUTICALS (REGN) rather than necessarily a brand-new position (though new positions also appear as buys when prior quantity was zero).
Is institutional interest in REGN increasing?
Institutional interest in REGN can be assessed by comparing the number of tracked funds adding or increasing positions versus those trimming or exiting across the periods shown. A higher number of additions typically signals increasing participation among large filers, but it should be read alongside position sizes and the full table.