US Options Data API

Underlying, root, expiration, strike, call or put, multiplier, exercise style, settlement type, deliverable, listing exchange, and effective dates define a usable contract. Non-standard deliverables after splits or mergers must remain distinguishable from standard 100-share contracts.

Confirm whether bid and ask represent the national best market, one exchange, or a vendor-constructed snapshot. Preserve price, size, venue, condition, source timestamp, receive timestamp, and an explicit stale or crossed-market policy.

Last price alone is ambiguous. Trade venue, size, sequence, correction or cancellation status, and condition codes determine whether an execution should update the last sale, volume, or an intraday signal.

Open interest is generally not an intraday counter like volume. Require the business date or as-of timestamp and never label a chain “real time” merely because its quotes are fresh.

Delta, gamma, theta, vega, and implied volatility depend on the option price, underlying price, rates, dividend assumptions, model, and calculation time. Store those inputs or the vendor methodology before comparing values across feeds.

Equity, ETF, and index options can differ in exercise style, settlement, tax treatment, multiplier, last trading time, and expiration behavior. Use US Eastern Time plus an exchange calendar rather than assuming every contract follows the equity close.

Include liquid and illiquid equities, ETFs, cash-settled indexes, weeklies, LEAPS, adjusted contracts, expired series, zero-bid options, and underlyings with recent corporate actions.

Compare the provider’s contract ID, symbol, underlying, expiration, strike precision, side, multiplier, deliverable, and active status. Write a rule for renamed, adjusted, expired, and later-corrected contracts.

Record source and receipt timestamps for quote, trade, underlying, Greeks, volume, and open interest. Determine whether each is live, delayed, end-of-day, cached, or computed on request.

Use a snapshot to establish chain state, then apply incremental events. Validate subscription acknowledgements, sequence gaps, reconnect behavior, duplicate messages, corrections, and a clean resnapshot procedure.

Distinguish a closed market, unknown underlying, no listed contracts, expired contract, entitlement failure, rate limit, partial chain, and temporary provider outage. An empty array should not carry every meaning.

Confirm display, non-display, derived-data, caching, user-count, and redistribution terms for the exact feed and user type. Technical access does not by itself grant production or redistribution rights.