Delta
Definition · Level 1 · Options basics
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Approximate change in an option’s price per $1 move in the underlying: 0 to 1 for calls, −1 to 0 for puts, about ±0.50 at the money. Also the hedge ratio, and a rough proxy (not the exact probability) for the chance of expiring in the money.
Example
A 0.40 call gains about $0.40 per share — $40 per contract — if the stock rises $1.
Where Tradecraft teaches it
Level 1 · Options basics, in the lesson “Reading the chain & opening vs closing”: Bid, ask, volume, open interest, IV, delta — and BTO/STO/BTC/STC.
Related terms
- Buy to close (BTC)Order that buys back an option you previously sold, ending your obligation.
- Buy to open (BTO)Order that creates or adds to a long option position — you become the holder.
- Implied volatility (IV)The volatility input that makes a pricing model reproduce an option’s market price, in annualized terms — often read as the move the market is…
- Open interestNumber of option or futures contracts outstanding — not yet closed, exercised or expired — each with one long and one short; reported once a day.
- Option chainTable of every strike for an expiry — usually calls on the left, puts on the right, strikes down the middle — with bid, ask, volume, OI, IV and delta.
- Sell to close (STC)Order that sells an option you own, exiting a long position and capturing both intrinsic and remaining time value.