MRK implied volatility
From the closing options book · October 20, 2026 · updated after every close
MRK's at-the-money implied volatility was 42.1% at the October 20, 2026 close. Over the past 252 sessions it ranged from 20.9% to 42.6%, putting today's level at an IV rank of 98 and IV percentile of 99.
MRK at-the-money IV, last 60 sessions
Options were pricing more movement than MRK actually delivered over the last 20 sessions (42.1% implied against 29.1% 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 MRK's own closing history.
These are the October 20, 2026 closing numbers. Members see MRK's map move live all session.
Common questions
42.1% at the money at the October 20, 2026 close.
98 over the past 252 sessions (IV percentile 99).
Its IV percentile is 99: high 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.