REGN's biggest one-day moves since 2021, and what happened next
Describes the past; not a signal. Pre-licensed data — internal estimates, to be re-verified after our licensed data rebuild.
Close-to-close daily changes from 1 Apr 2021 to 4 Nov 2026 (1406 sessions). Later changes are measured from the close on the day of the move.
Biggest one-day falls
Of these 10, 4 were higher 21 sessions later · n = 10 · could be chance.
| Date | One-day change | After 5 sessions | After 21 sessions | After 63 sessions |
|---|---|---|---|---|
| 30 May 2025 | -19.0% | +0.6% | +9.1% | +18.4% |
| 18 May 2026 | -9.8% | +0.8% | -3.5% | +28.7% |
| 31 Oct 2024 | -9.2% | -1.6% | -9.1% | -16.8% |
| 27 Jun 2023 | -8.7% | +0.2% | +4.0% | +16.2% |
| 9 Jan 2023 | -7.7% | +7.0% | +10.2% | +20.4% |
| 6 May 2025 | -7.5% | +2.8% | -13.4% | -0.5% |
| 29 Apr 2025 | -6.9% | -1.8% | +6.6% | -2.4% |
| 29 Apr 2026 | -6.2% | +5.1% | -10.4% | +7.6% |
| 4 May 2023 | -6.1% | -1.1% | -0.5% | +1.7% |
| 4 Apr 2025 | -6.1% | -3.4% | -2.6% | -4.3% |
Biggest one-day rises
Of these 9, 6 were higher 21 sessions later · n = 9 · could be chance.
| Date | One-day change | After 5 sessions | After 21 sessions | After 63 sessions |
|---|---|---|---|---|
| 8 Sep 2022 | +18.8% | -0.4% | +1.9% | +7.8% |
| 30 Oct 2026 | +13.3% | pending | pending | pending |
| 28 Oct 2025 | +11.8% | -4.0% | +19.9% | +14.5% |
| 12 May 2025 | +9.1% | +3.6% | -9.8% | -3.2% |
| 23 Mar 2023 | +6.8% | +1.2% | -0.6% | -2.8% |
| 3 Oct 2022 | +6.7% | -0.6% | +3.4% | -2.0% |
| 1 Oct 2025 | +6.7% | -6.0% | +9.0% | +28.7% |
| 30 Jul 2026 | +6.2% | +4.6% | +7.6% | +10.1% |
| 28 Oct 2021 | +6.0% | +3.6% | +4.7% | -0.0% |
| 3 Aug 2022 | +5.9% | +5.4% | -1.3% | +24.8% |