How to read an options chain
The short answerAn options chain lists every call and put of one expiration, strike by strike: calls on the left, puts on the right, strikes in the middle. For each contract it shows the bid and the ask (what you can sell and buy at), the last trade, volume, open interest, implied volatility and often the greeks such as delta.
1. Pick the expiration
A chain shows one expiration at a time. Short expirations are cheaper and react faster; long ones cost more and give the trade time. SPY lists an expiration every weekday.
2. Find the price among the strikes
Calls with a strike below the price and puts with a strike above it are in the money (they have value if exercised now); most chains shade them. The strikes closest to the price are at the money.
3. Read the price: bid, ask, mark
The bid is the most a buyer will pay, the ask the least a seller will take; the middle is the “mark”. A quote of 2.50 means $250, because one contract covers 100 shares. A wide gap between bid and ask is a cost to you — liquid names like SPY have spreads of a cent or two.
4. Volume and open interest
Volume is today’s trading; open interest is the contracts still open (the difference). Busy strikes are easier to trade at a fair price.
5. Implied volatility and delta
Implied volatility is the volatility the price implies — compare it across strikes to see the skew (puts below the price usually carry a higher IV than calls above it). Delta is how much the option moves per $1 in the stock, and is often read as a rough chance of finishing in the money: a 0.30-delta call has about a 30% chance.
6. Read the chain as a whole
Put all strikes together and the chain tells a story: where open interest is heaviest (the walls), where the options would be worth least (max pain), how dealers are positioned (gamma exposure), and how big a move is priced (the expected move). That summary is what every ticker page on this site shows.
Live example: SPY and QQQ today
From the close of Fri, Nov 13, 2026 — this box is rebuilt after every trading day.
SPY closed at 754.21 on Nov 13, 2026. The strikes around the price, all expirations together (a broker’s chain shows one expiration at a time, with bid and ask):
| Strike | Call OI | Call IV | Put IV | Put OI |
|---|
| 735 call ITM | 31,989 | 18.1% | 17.8% | 171,153 |
| 740 call ITM | 40,877 | 17.3% | 17.5% | 174,147 |
| 745 call ITM | 42,277 | 16.7% | 16.8% | 106,457 |
| 750 call ITM | 102,112 | 16.2% | 16.1% | 217,980 |
| 755 put ITM | 61,156 | 15.5% | 15.5% | 91,100 |
| 760 put ITM | 102,690 | 14.6% | 14.8% | 117,936 |
| 765 put ITM | 80,566 | 14.2% | 14.7% | 70,276 |
| 770 put ITM | 149,688 | 13.3% | 13.8% | 90,536 |
Notice the skew: implied volatility rises as the strikes go down — 17.8% at 735 against 13.3% at 770. Protection below the price costs more than upside above it.
The full strike table is a free CSV on the SPY page.
Questions and answers
What do the numbers in an options chain mean?
For each strike: the bid and ask (the prices to sell and buy), the last trade, volume (traded today), open interest (contracts open), implied volatility and the greeks like delta.
Why is an option quoted at 1.20 but costs $120?
One standard US equity option covers 100 shares, so the quoted price is multiplied by 100.
What does in the money mean?
A call is in the money when the stock is above its strike; a put when the stock is below its strike. It would be worth something if exercised now.
All 10 lessons: Learn · every term in one long page: the full guide · the numbers for any ticker: ETFs, stocks. For education only — not investment advice.