The Greeks
The collective name for the sensitivity measures — delta, gamma, theta, vega, rho — that describe how an option's price responds to changes in market variables.
The Greeks are the partial derivatives of an option's price with respect to each key input: underlying price (delta, gamma), time (theta), volatility (vega), and interest rates (rho).
Together they form a complete risk dashboard for an options position or portfolio. A risk manager checks net delta (directional exposure), net gamma (acceleration risk), net theta (daily decay), and net vega (volatility exposure) to understand P&L behaviour under different market scenarios.
Greeks interact: a short-gamma, long-theta position (selling short-dated options) collects decay but can suffer large losses if spot moves sharply.