CELESYS LEARNING / EDUCATIONAL

How to read an option chain

Understand strikes, expiry, bid/ask spreads, open interest and implied volatility before comparing India or US options.

An option chain groups call and put contracts by strike price and expiration. Start by selecting the correct underlying and expiry. A NIFTY index option and a US ETF option have different contract specifications; a displayed premium alone does not tell you the total cost.

1. Confirm the contract

Check the exchange, underlying, call or put, strike, expiration and contract multiplier. Contract size and settlement rules must come from the exchange or broker. Do not apply a US equity-option multiplier to an Indian index contract.

2. Read the bid and ask first

The bid is the displayed buying interest; the ask is the displayed selling interest. Neither guarantees a fill. The last traded price can be old even when the market has moved. A wide bid/ask spread increases the potential cost of entering and exiting. A missing or crossed quote needs investigation.

3. Compare activity without guessing direction

Volume counts trading activity over the provider's reporting period. Open interest counts outstanding contracts and can update on a different schedule. Every contract has both a buyer and a seller: high call open interest alone does not prove bearish positioning.

4. Check volatility and time

Implied volatility reflects the volatility priced into an option, not a guaranteed forecast. Delta, gamma and theta are model sensitivities that change with price, volatility and time. A correct directional view can still lose money when the premium falls after a volatility event.

5. Check the source time

Celesys separates the time a snapshot was fetched from quote timestamps. When the provider does not supply quote timestamps, freshness remains unverified. Use your broker's current quotes, contract details and event information before making a decision.

Options Industry Council: options basics · NSE option chain and explanatory notes

Explore the India chain or US chain. Data availability is shown in the workspace.