Delta: how much the option moves when the stock moves $1
A 0.50 delta call gains about $0.50 when the stock rises $1. Drag spot or strike in the panel and the Greeks recompute on every tick.
- Call Delta: 0 to 1.0 (0 = OTM, 0.5 = ATM, 1.0 = deep ITM)
- Put Delta: −1.0 to 0 (negative because puts gain when the stock falls)
