Separate current directional sensitivity from the rate at which that sensitivity changes as the underlying moves.
What delta answers
Delta estimates how option value responds to the next small underlying move. It helps describe direction, size hedges and convert options into share-equivalent exposure.
What gamma answers
Gamma estimates how delta itself changes. High gamma means the current hedge ratio can become stale quickly, especially when the stock trades near a strike close to expiration.
Read them together
A low-delta option can become high delta after a large favorable move if it has positive gamma. A short option can develop increasingly adverse delta because negative gamma works against the position.
A practical example
A call begins with delta 0.40 and gamma 0.07. After a $1 rise, delta is roughly 0.47; after another $1, simply adding gamma again is only approximate because gamma has changed too.
This simplified example holds other inputs constant to isolate directional exposure. Live option prices also reflect the underlying price, time decay, rates, dividends, liquidity and transaction costs. Greeks are theoretical estimates, not guarantees.
Frequently asked questions
Which Greek affects price first?
Delta describes the first-order price response; gamma refines how that response changes.
Is high gamma good?
It supports convexity for long options but creates instability and risk for short options.
Can delta be stable with high gamma?
Only briefly; a meaningful underlying move changes it quickly.
Continue the Delta Effect cluster
Explore related guides: Gamma Risk Near Option Expiration · How to Read Delta in an Option Chain · Option Delta for ITM, ATM and OTM Contracts. For a structured sequence, use the free Level 6 – Delta Effect course.
Advanced strategy: Read the Backspread guide and take the free Level 14 course.
Options involve risk and are not suitable for every investor. This material is educational and is not investment, tax or legal advice. Greeks are theoretical estimates, and contract terms and broker requirements can vary.