Delta, Gamma, Theta, and Vega are critical metrics in options trading that determine how option prices respond to various factors. Delta measures the change in an option's price with a Rs.1 movement in the underlying asset, with call options having a Delta from 0 to 1 and put options from 0 to -1. For instance, a call option with Delta 0.4 will gain Rs.4 if the underlying stock rises by Rs.10. Gamma reflects how Delta changes with price movements, which can accelerate profits if the trader's direction is correct. Theta, known as the silent destroyer, measures time decay and negatively impacts option value as expiration nears. For example, an ATM call option bought at Rs.6 can lose value due to time decay, even if the underlying stock rises. Lastly, Vega assesses how sensitive an option's price is to changes in implied volatility, which can significantly affect premiums around major market events. Understanding these Greeks allows traders to make informed decisions rather than relying on luck.