Futures and Options are financial derivative contracts whose value is derived from an underlying asset (stocks, indices, commodities). A futures contract obligates the buyer to purchase (or sell) the asset at a predetermined price on a future date. An options contract gives the buyer the right - but not the obligation - to buy or sell at a set price before expiry.

In futures, both buyer and seller are obligated to execute the contract at the agreed price. In options, only the seller (writer) is obligated; the buyer has the right to exercise or not. Futures carry unlimited risk for both parties; options buyers risk only the premium paid.

Open Interest (OI) is the total number of outstanding (open) derivative contracts that have not yet been settled. Rising OI with rising price indicates fresh long build-up (bullish); falling OI with rising price indicates short covering.

An option chain is a table that shows all available call and put options for a particular stock or index across different strike prices and expiry dates. It displays data like OI, volume, implied volatility, and the last traded price for each contract.

NSE F&O contracts trade from 9:15 AM to 3:30 PM IST on all trading days. Commodity and currency derivatives trade for extended hours.