Delta — Directional Exposure in One Number
Share equivalents, hedging ratios, and what 0.50 actually means
If you only learn one Greek, learn Delta. Every other Greek is a refinement of how Delta behaves under conditions — Gamma is how Delta changes when the stock moves, Theta is how Delta changes when time passes, Vega is how Delta changes when volatility shifts. The Delta itself is the simplest possible answer to the question 'how much does this option's value change when the underlying stock moves a dollar?
' Concretely: a Delta of 0.50 means the option's price moves about $0.50 for every dollar move in the underlying.
A Delta of 0.20 means $0.20 per $1 move.
Delta lives between 0.00 (deep out-of-the-money calls move barely at all when the stock changes) and 1.00 (deep in-the-money calls move dollar-for-dollar with the stock — they have become essentially share-equivalent positions).
For puts, Delta is negative, ranging from -1.00 to 0.00 in the mirror-image pattern.
That is the opening. Finishing a lesson is where it stops being interesting and starts being useful: the full lesson runs to 7 sections and ends with 6 practice questions. A free account is what opens the rest, and the other 255 lessons in the Academy with it. No card.
What this lesson covers
- 1Delta across moneyness — the canonical ladder
- 2Delta is not static — every other Greek tells you how it moves
- 3Delta in closed form (BSM)
- 4Delta evolution as a 30-day call moves through expiration
- 5Why ATM weekly options have the most violent Delta swings
- 6Where to see this on the platform
- 7Summary