Delta

Delta is the most intuitive of the options Greeks. It measures how much an option's price changes for every $1 move in the underlying stock. A call option with a delta of 0.50 gains $0.50 when the stock rises $1 and loses $0.50 when the stock drops $1. Put options have negative delta: a put with -0.40 delta gains $0.40 when the stock drops $1.

Delta also serves as a rough approximation of the probability that an option will expire in the money. A 0.50 delta option has roughly a 50% chance of finishing ITM (this is an approximation, not exact). Deep ITM options have deltas near 1.0 (high probability), while far OTM options have deltas near 0 (low probability). This probability interpretation is widely used for strike selection — selling a 0.30 delta put means approximately a 70% chance the stock stays above your strike.

For portfolio management, delta helps you understand your directional exposure. If you own calls with a total delta of 200, your position behaves roughly like owning 200 shares of stock. This allows you to compare and combine different options positions into an overall directional view. Options Pilot uses delta-based frameworks throughout its analysis, from spread quality measurements by delta range in the Liquidity pillar to strategy recommendations specifying optimal delta targets for different approaches.