Cboe's Volatility Index: how much options traders expect the S&P 500 to swing over the next 30 days, annualised. Above 30 is usually read as fear, below 15 as calm.
Hover to inspect recorded values. Click to pin a point; click again to release. Drag between two points to measure the return over that span. Use arrow keys to move, shift with an arrow key to extend a span, Home or End to jump, and Escape to clear.