Vega

Every option trades in two markets at once: the stock's price and the market's forecast of how much it will move — implied volatility. Vega is your exposure to the second: the dollars an option gains or loses per 1-point IV change, with the stock frozen. An ATM 30-day call carries about $11 of vega per point per contract; the 180-day version about $28, because vega grows with time to expiry.

The classic ambush is the earnings IV crush. Pre-report options carry inflated IV; when the news lands, the uncertainty is spent and IV collapses — so a buyer can be right on direction and still lose, because the vega loss outweighs the delta gain. The interactive curve lets you stage it: park IV at 60%, crush it to 35%, and read the damage across 14, 30, 90 and 180-day expiries.

The signs are simple: long options are long vega, short options are short vega. Vega concentrates at the money and in long-dated contracts, and it lives entirely in extrinsic value.

For premium sellers the punchline is structural: selling a cash-secured put or covered call is selling volatility. A vol spike marks a short put underwater before the stock ever nears the strike, while the persistent gap between implied and subsequently realized volatility — the volatility risk premium — is a large part of why the harvest exists at all.