Delta, Gamma, Theta, Vega — plain English (no textbook definitions)

Been trading options for 2 years and I still catch myself Googling the Greeks. So I wrote these out in plain English for myself. Maybe useful for others. Delta (\~0.50 ATM): How much your option moves per $1 stock move. A 0.50 delta call gains $0.50 if stock goes up $1. Simple. Gamma: How fast delta changes. High gamma = your delta is moving fast. This is why ATM options explode in value right before expiration. Theta: Time decay. Every day you hold a long option, you lose theta. Selling options = theta works FOR you. This is why theta gang exists. Vega: Sensitivity to implied volatility. Buy options before earnings (IV goes up = vega profits). Sell options after earnings (IV crush hurts buyers, helps sellers). The part nobody explains: these don't work in isolation. A high-vega trade going into earnings + high theta on a weekly = you're fighting two forces at once. Happy to discuss how to use all four together when evaluating a trade.