What Is Options Delta?
Delta measures how much an option's price changes for every $1 move in the underlying stock. Calls have positive delta (0 to 1), puts have negative delta (-1 to 0).
Definition
Delta is one of the options Greeks — it measures how much an option's price moves for every $1 change in the underlying stock price. A call option with a delta of 0.60 gains $0.60 in value for every $1 the stock rises. Calls have positive delta (0 to 1.0); puts have negative delta (0 to -1.0).
Delta also approximates the probability that an option will expire in the money. A 0.30 delta call has roughly a 30% chance of expiring ITM. A 0.70 delta call has roughly a 70% chance. This makes delta a useful tool for position sizing and strike selection.
Deep in-the-money options have delta near 1.0 (calls) or -1.0 (puts), moving almost dollar-for-dollar with the stock. Far out-of-the-money options have delta near zero — they barely move even when the stock does.
Real-World Example
You buy a call with a 0.40 delta when AAPL is at $180. If AAPL rises to $185 (up $5), your call gains approximately $2.00 (0.40 × $5 = $2.00), moving from $4 to $6. The actual move may differ due to gamma and other factors.
Why It Matters
Delta is the single most important Greek for understanding how your position will behave — it tells you your directional exposure and helps you compare different strikes apples-to-apples.
Get Glen’s Updates
Investing insights, new tools, and whatever I’m building this week. Free. No spam.
Unsubscribe anytime. I respect your inbox more than Congress respects property rights.
Frequently Asked Questions
What is a good delta for a covered call?
Most covered call sellers target a delta between 0.20 and 0.35 — out of the money enough that the stock is unlikely to be called away, but close enough to collect meaningful premium. Lower delta = more conservative, higher delta = more aggressive.
Does delta change?
Yes — delta changes as the stock price moves, as time passes, and as volatility changes. Gamma measures the rate of change of delta. At-the-money options have the highest gamma, so their delta changes most rapidly as the stock moves.
What does it mean to be delta neutral?
Delta neutral means your portfolio has a net delta of zero — price moves in the underlying don't change your P&L. Market makers and professional traders often hedge to delta neutral using a combination of options and shares. Retail traders rarely need delta neutrality.
Related Terms
Recommended Resources
Tools & books I actually use and recommend
SeekingAlpha Premium
Quant ratings, earnings transcripts, and the stock analysis community where I published 300+ articles.
Try SeekingAlphaA Random Walk Down Wall Street
Burton Malkiel's classic case for index investing. The book that convinced millions to stop stock-picking.
View on AmazonThe Little Book of Common Sense Investing
John Bogle's manifesto on why low-cost index funds beat everything else. Straight from the founder of Vanguard.
View on AmazonSome links above are affiliate links. I only recommend products I personally use. See my full disclosures.