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REGN +13.4%: one of its biggest daily moves this year. REGENERON PHARMACEUTICALS, INC. moved 12.8 points more than its sector, on 3.6× its usual volume.

2026-10-30 · REGN

REGN +13.4%: one of its biggest daily moves this year

REGENERON PHARMACEUTICALS, INC. moved 12.8 points more than its sector, on 3.6× its usual volume.

The story in plain words

Friday, October 30, 2026. REGN +13.4%: one of its biggest daily moves this year. REGENERON PHARMACEUTICALS, INC. moved 12.8 points more than its sector, on 3.6× its usual volume.

What the data shows for Regeneron Pharmaceuticals (REGN): REGN +13.4% today. Its sector fund (XLV) +0.6% today. S&P 500 (SPY) −1.9% today.

Worked out from that data: 12.8 points more than its sector. Volume 3.6× its 20-day average. Its biggest daily move in the past 250 trading days.

Possible contributors. These line up in time with the move; they are not confirmed causes: News: “Regeneron Pharmaceuticals, Inc. Q3 2026 Earnings Call Summary” (Published around the move. Timing only, not a confirmed cause). News: “What Just Happened To Alnylam Stock?” (Published around the move. Timing only, not a confirmed cause). 10-Q filed (Filed around the move. Timing only). 8-K filed: Earnings results (Filed around the move. Timing only).

About the company: Regeneron Pharmaceuticals trades as REGN and is part of the S&P 500, in the Health Care sector (Biotechnology), headquartered in Tarrytown, New York, founded in 1988.

This is one of CookieStocks’ daily stock stories about unusually large one-day price moves in S&P 500 stocks, measured against each stock’s own history, its sector and its usual volume. Stories are found automatically each trading day from market data and SEC filings, and every claim is labelled as observed, calculated or a possible contributor. Statistics only, not investment advice.

Prove it

Every claim on the graphic, labelled: observed (straight from the data), calculated (worked out from it), or possible contributor (lines up in time, not a confirmed cause).

  • OBSERVED
    REGN +13.4% todayOct 30, 2026, 4:35 PM ET
  • OBSERVED
    Its sector fund (XLV) +0.6% todayOct 30, 2026, 4:35 PM ET
  • CALCULATED
    12.8 points more than its sectorHow: stock return − sector fund return · Oct 30, 2026, 4:35 PM ET
  • OBSERVED
    S&P 500 (SPY) −1.9% todayOct 30, 2026, 4:35 PM ET
  • CALCULATED
    Volume 3.6× its 20-day averageHow: today’s volume ÷ average of the last 20 days · Oct 30, 2026, 4:35 PM ET
  • CALCULATED
    Its biggest daily move in the past 250 trading daysHow: share of past daily moves smaller in size · Oct 30, 2026, 4:35 PM ET
  • POSSIBLE CONTRIBUTOR
    News: “Regeneron Pharmaceuticals, Inc. Q3 2026 Earnings Call Summary”Published around the move. Timing only, not a confirmed cause. · Oct 30, 2026, 12:55 PM ET
  • POSSIBLE CONTRIBUTOR
    News: “What Just Happened To Alnylam Stock?”Published around the move. Timing only, not a confirmed cause. · Oct 30, 2026, 12:51 PM ET
  • POSSIBLE CONTRIBUTOR
    10-Q filedFiled around the move. Timing only. · Source: SEC EDGAR · Oct 30, 2026, 4:00 PM ET
  • POSSIBLE CONTRIBUTOR
    8-K filed: Earnings resultsFiled around the move. Timing only. · Source: SEC EDGAR · Oct 30, 2026, 4:00 PM ET

Regeneron Pharmaceuticals (REGN) financials and filings →

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Statistics only, not investment advice. Past moves don’t predict future ones. Data as of Oct 30, 2026, 4:35 PM ET.