SO implied volatility
From the closing options book · October 20, 2026 · updated after every close
SO's at-the-money implied volatility was 21.1% at the October 20, 2026 close. Over the past 241 sessions it ranged from 14.3% to 34.7%, putting today's level at an IV rank of 33 and IV percentile of 66.
SO at-the-money IV, last 60 sessions
Options were pricing more movement than SO actually delivered over the last 20 sessions (21.1% implied against 19.0% realized).
IV rank places today's IV between the period's low (0) and high (100); IV percentile is the share of sessions with lower IV. Both use SO's own closing history.
These are the October 20, 2026 closing numbers. Members see SO's map move live all session.
Common questions
21.1% at the money at the October 20, 2026 close.
33 over the past 241 sessions (IV percentile 66).
Its IV percentile is 66: middling against its own past year.
Compare: implied volatility on other tickers
Measured from the closing options book and rebuilt after every close. Nothing on this page is live. Levels are where dealer hedging is concentrated, not targets or forecasts. Not investment advice.