# Options chain

Also written option chain.

*https://stockmarketstack.com/glossary/options-chain · next to Stock Market Data APIs*

**Definition:** Every listed option on one underlier, arranged by expiry and strike, with calls and puts and a quote on each line. It is a data object rather than a screen, and a large one: hundreds of series per liquid name. The word says nothing about whether the quote is one venue's or the consolidated best, how fresh it is, or whether any calculated field comes with it.

## How it works

A chain is the cross product of three things for one underlier: every expiry the exchanges list,
every strike listed at that expiry, and both a call and a put at each. For a liquid US name that is
hundreds of rows, and across the whole market it is an enormous object — the revised OPRA capacity
projections of 15 September 2025 project 13.575 billion messages a day effective July 2026, rising to
14.964 billion by July 2027, and that is for one of two redundant streams. Options are the asset
class where the size of the data shows through the shape of the product.

Each row carries a quote and a few counts. What the word "chain" does not tell you is any of the
following, and all four differ between providers:

**Whose quote.** A bid and ask on a line can be the best available across every US options exchange,
or the best on one of them. Those are different numbers, and the consolidated one is what regulation
and clearing treat as the market price of a quote — see [NBBO](https://stockmarketstack.com/glossary/nbbo) for what it is and is
not. A single-venue quote is not wrong; it is answering a narrower question, and nothing in a JSON
response says which question was answered.

**How fresh.** Fifteen minutes is the standard free delay, on the instrument whose price is a
function of an underlying that has since moved. A delayed chain is entirely usable for studying past
behaviour, building an interface or screening; it is a record rather than a market.

**How wide.** Full chains are expensive to serve, so free and cheap endpoints trim — near-dated
expiries, strikes near the money, a row cap. The trim is rarely documented and never flagged in the
payload.

**What is calculated.** Implied volatility and the greeks are not fields in the feed. They are
outputs computed on top of it, which is why they are sold separately and why two providers disagree
about them: see [implied volatility](https://stockmarketstack.com/glossary/implied-volatility) and
[greeks](https://stockmarketstack.com/glossary/greeks).

## What a cheap chain leaves out, in order

Working down from what costs the vendor least to what costs it most:

1. **Live quotes.** Delay is free; real time is per subscriber on a published schedule. On the OPRA
   fee schedule dated 26 February 2026 the professional display device fee is $31.50 a month and the
   non-professional subscriber fee is $1.25, falling to $0.60 at volume — and redistribution is $1,500
   a month, $650 for query service only.
2. **The consolidated best rather than one venue's.** A vendor connected to fewer venues has a
   cheaper bill and a narrower quote.
3. **The full width of the chain.** Every expiry, every strike.
4. **Open interest aligned to the right session.** It is a cleared figure, produced once a day after
   the clearing house pairs opening against closing positions, so it sits on a different clock from
   the quote beside it. [Open interest](https://stockmarketstack.com/glossary/open-interest) has the mechanics.
5. **Implied volatility, then the greeks.** The modelling layer, and the last thing a free tier
   carries because it is the one that requires ongoing work rather than a licence.

## Why it matters here

The single question to ask of a card that says it returns options chains is which of those five it
actually includes, because the phrase covers all of them. The catalogue's own answers are collected
in [options data](https://stockmarketstack.com/collections/options-data), and
[how to get an options chain](https://stockmarketstack.com/how-to/get-an-options-chain) walks the free, cheap and file-based
routes with the figures.

Two distinctions worth carrying into that reading.

**A chain is not a surface.** A chain is the quotes as they stand; a fitted volatility surface is
somebody's model over them, maintained consistently across strikes, expiries and years.
[ORATS](https://stockmarketstack.com/tools/orats) sells the second, a general-purpose API sells the first, and they are not
substitutes even though both arrive as rows about the same contracts.

**A live chain is not a bigger version of history.** Options history is every strike of every expiry
of every underlier for every day, which is why it ships as files rather than as a stream —
[Cboe DataShop](https://stockmarketstack.com/tools/cboe-datashop) prices it per dataset, date and symbol. A card that sells one
shape often does not sell the other at any price, and reading a live-chain endpoint as evidence of
history is a common and expensive mistake.

The licensing note applies here with the largest multipliers on the site. A chain you look at is
display use; a program acting on a live chain is not, and the moment a live options quote reaches
somebody who is not you it is redistribution. [Non-display use](https://stockmarketstack.com/glossary/non-display-use) and
[redistribution](https://stockmarketstack.com/glossary/redistribution) are separate permissions with separate prices, and
[what real-time market data costs](https://stockmarketstack.com/guides/real-time-market-data-fees) has the stack.

## Where you will meet this

- [yfinance](https://stockmarketstack.com/tools/yfinance.md)
- [EODHD](https://stockmarketstack.com/tools/eodhd.md)
- [Alpha Vantage](https://stockmarketstack.com/tools/alpha-vantage.md)
- [ORATS](https://stockmarketstack.com/tools/orats.md)
- [Cboe DataShop](https://stockmarketstack.com/tools/cboe-datashop.md)
- [Market Chameleon](https://stockmarketstack.com/tools/market-chameleon.md)
- [Composer](https://stockmarketstack.com/tools/composer.md)
- [Dataroma](https://stockmarketstack.com/tools/dataroma.md)
- [Equibles](https://stockmarketstack.com/tools/equibles.md)
- [Financial Modeling Prep](https://stockmarketstack.com/tools/financial-modeling-prep.md)
- [MotiveWave](https://stockmarketstack.com/tools/motivewave.md)
- [NautilusTrader](https://stockmarketstack.com/tools/nautilus-trader.md)

## FAQ

### Why do two providers return different numbers of rows for the same ticker?

Because a full chain is large and most endpoints truncate it. The usual trims are near-dated expiries only, strikes within some band of the current underlying price, and a cap on rows per request. None of them is announced in the response, so a chain that looks complete may be a window onto one. Count the expiries you got against the expiries the exchange lists.

### Is the bid and ask on a chain the price I would trade at?

Only if it is live and consolidated, and on a free tier it is usually neither. A delayed quote is a record of where the market was, and a single venue's best is a narrower question than the consolidated best across every options exchange. Both are legitimate products; neither is interchangeable with the other.

## Sources

1. [Options Price Reporting Authority Fee Schedule](https://cdn.opraplan.com/documents/OPRA_Fee_Schedule.pdf) — Options Price Reporting Authority, 2026-02-26
2. [Revised OPRA Capacity Projections, notice to OPRA Multicast Data Subscribers](https://cdn.opraplan.com/documents/notices/OPRA_Capacity_Projections_Update_0925.pdf) — Securities Industry Automation Corporation (OPRA), 2025-09-15
3. [Options FAQ, General Information](https://www.optionseducation.org/referencelibrary/faq/general-information) — The Options Industry Council, read 2026-09-21

*Last updated 2026-09-21. A reference page, corrected in place — not a dated post.*