Vega

Vega is one of the options Greeks — it measures how much an option's price should change for each one-point shift in implied volatility. An option with a vega of 0.12 would gain roughly $0.12 if implied volatility rose by one point, even with no move in the stock at all. Vega runs highest for at-the-money options with more time until expiration, and it's the mechanism behind "IV crush" — the sharp price drop that can follow a known event like earnings once uncertainty resolves and implied volatility collapses. It describes a source of price movement that has nothing to do with the stock's direction: a stock that doesn't move at all can still shift an option's price purely from IV rising or falling.