Greeks – A set of metrics used to estimate the potential risks and rewards associated with a particular investment. The ‘greeks’ (Delta, Vega, Gamma, Theta, Rho) measure the sensitivity of an option’s price to changes in various components such as underlying stock price, volatility, interest rates and time decay. By studying these greeks, investors are able to better gauge the potential return on an option contract, allowing them to make more informed decisions about their investments.