Option traders rarely need an entire options universe in one shot. What’s usually needed is a fast, repeatable sequence of API calls that mirrors real decision-making:
- confirm symbol coverage and build a watchlist
- detect recent contract activity
- load a focused chain slice (expiry window + strike band)
- deep-dive a single contract’s history (validation and research)
- identify key strikes using open interest concentration
All requests below are browser-ready and were executed successfully with real responses (JSON files attached). Full API documentation could be found here.
1) Coverage and watchlist foundation: list underlyings with options coverage
Let’s start with the list of available tickers:
https://eodhd.com/api/mp/unicornbay/options/underlying-symbols?api_token={YOUR_API_TOKEN}
The response included 6423 US tickers (January, 2026)
2) Activity scan: contracts updated/traded in a time window
Many trading workflows start with “what’s active recently?” This call pulls contracts for a symbol within a time window and includes key trading fields such as last, volume, open_interest, volatility, and the Greeks.
https://eodhd.com/api/mp/unicornbay/options/eod?filter[underlying_symbol]=AAPL&filter[tradetime_from]=2025-02-01&filter[tradetime_to]=2025-04-03&fields[options-eod]=contract,underlying_symbol,type,exp_date,strike,last,volume,open_interest,volatility,delta,gamma,theta,vega,rho,tradetime&sort=strike&page[limit]=25&compact=1&api_token={YOUR_API_TOKEN}
Download JSON response
A large set of contracts and metrics for AAPL in the specified window (meta.total = 88679) including rows with non-zero volume, suitable for building activity screens.
Common uses
- build “recent activity” feeds per ticker
- locally rank by volume, open_interest, or volatility (then drill down)
- discover which expirations/strikes are worth pulling as a chain slice
3) Chain slice: expiry window + strike band
Pulling a full chain can be heavy. Traders typically look at near expirations and strikes around spot (ATM ± N strikes). This request does exactly that and returns Greeks, implied volatility, and open interest for fast decision-making.
https://eodhd.com/api/mp/unicornbay/options/contracts?filter[underlying_symbol]=AAPL&filter[exp_date_from]=2025-02-01&filter[exp_date_to]=2025-03-31&filter[strike_from]=150&filter[strike_to]=250&fields[options-contracts]=contract,underlying_symbol,type,exp_date,strike,last,volume,open_interest,volatility,delta,gamma,theta,vega,rho,dte&sort=strike&page[limit]=25&compact=1&api_token={YOUR_API_TOKEN}
A manageable subset of the AAPL chain (meta.total = 558) including both calls and puts, with Greeks and implied volatility.
Common uses
- build an ATM-focused chain UI
- pick strikes by delta bands (e.g., 0.30 delta)
- compare volatility across strikes to observe skew
- select candidate contracts for deeper analysis
4) Single-contract deep dive: EOD history for one option contract
After a candidate contract is identified, the next step is understanding its behavior over time. An EOD series supports monitoring and backtesting: price history, implied volatility shifts, Greek dynamics, and changes in open interest.
Request (contract selected from the chain slice):
https://eodhd.com/api/mp/unicornbay/options/eod?filter[contract]=AAPL250321C00150000&fields[options-eod]=contract,bid_date,open,high,low,last,volume,open_interest,volatility,delta,gamma,theta,vega,rho,tradetime&sort=-exp_date&page[limit]=50&compact=1&api_token={YOUR_API_TOKEN}
A time series with timestamps in bid_date and fields including OHLC, volume, open_interest, volatility, and the Greeks. The executed response returned meta.total = 289 rows.
Common uses
- track whether open_interest is building or fading
- study implied volatility expansion/crush (especially around events)
- evaluate decay via theta through time
- build backtests for entry/exit rules based on IV, OI, or Greek thresholds
5) Key strike discovery: open interest hotspots for a specific expiry
Open interest concentration helps identify “important strikes” where positioning clusters. Traders use these areas for strike selection, liquidity checks, and expiry-related risk assessment (including pin-risk considerations).
https://eodhd.com/api/mp/unicornbay/options/contracts?filter[underlying_symbol]=AAPL&filter[exp_date_eq]=2025-03-21&filter[type]=call&filter[strike_from]=120&filter[strike_to]=220&fields[options-contracts]=contract,underlying_symbol,exp_date,type,strike,last,volume,open_interest,volatility,delta,gamma,theta,vega,rho,dte&sort=strike&page[limit]=200&compact=1&api_token={YOUR_API_TOKEN}
A strike-banded set of calls for that expiry (meta.total = 35) with open interest, implied volatility, and Greeks.
Open interest hotspots in the executed response
- Strike 220: open_interest = 36823
- Strike 200: open_interest = 30635
- Strike 210: open_interest = 22476
Additional notable strikes included 185 (open_interest = 6756) and 190 (open_interest = 6543).
Common uses
- identify the most crowded strikes for an expiry
- choose spread wings where liquidity and positioning are concentrated
- combine open interest with volume and volatility to find strikes with both interest and activity
What this sequence provides for options trading
This sequence forms a practical pipeline:
- The coverage call defines the tradable universe and supports watchlists and UI symbol search
- The activity window highlights where contracts are updating and where attention may be concentrated
- The chain slice provides a tradeable view of strikes/expirations with Greeks and implied volatility
- The contract history supports validation and research by showing how pricing, IV, and Greeks evolved
- The open interest hotspot view highlights key strikes for execution and positioning-based context
Together, these calls support the most common options tasks: scanning for activity, selecting contracts, understanding risk via Greeks and IV, and choosing strikes informed by open interest distribution.
