Native IEX Quotes

Top-of-Book Pricing and BBO Liquidity from the IEX Exchange

Access historical Level 1 quote updates directly from IEX through FinFeedAPI. Retrieve top-of-book bid and ask prices, quote sizes, pre/post-market indicators, symbol availability states, and nanosecond timestamps.

Native IEX Level 1 Quotes preserve every top-of-book price level update published by IEX without aggregation or sampling, making them essential for best bid and offer (BBO) reconstruction, spread analysis, price impact measurement, and real-time quote snapshot backtesting.

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What Are Native IEX Level 1 Quotes?

Native IEX Level 1 Quotes represent continuous top-of-book bid and ask liquidity contributions generated on the Investors Exchange.

Unlike aggregated candle data (OHLCV), which summarizes activity over fixed time intervals, Level 1 Quotes capture every discrete top-of-book update at the exact moment bid or ask liquidity changes. Each record details the highest buy price (bid), lowest sell price (ask), corresponding share quantities, precise timestamps, and session state indicators.

The Native IEX Level 1 Quote dataset provides raw top-of-book prints exactly as generated by the IEX matching engine. It allows developers to evaluate bid-ask spreads, track quote persistence, monitor pre/post-market price action, and verify stock trading availability.

Unlike Level 2 Price Levels or Level 3 Order Book data, which expose multi-tier depth or full order lifecycle state (adds, modifies, cancels), Level 1 Quotes focus strictly on the immediate top-of-book executable price boundary.

Unlike Trades, which record finalized executions where liquidity was consumed, Level 1 Quotes capture resting liquidity commitments available before an execution takes place.

Developers routinely combine Native IEX Level 1 Quotes with Trades, Level 2 Price Levels, and Level 3 Order Books to evaluate fill quality, calculate slippage against BBO, and study microstructural liquidity dynamics.

What's Included?

Each quote record describes a single top-of-book update on the IEX market.

Field	What it means
symbol	Stock symbol identifier associated with the quote update.
timestamp	UTC ISO 8601 timestamp when the quote update was generated.
timestamp_nanos	Nanosecond-resolution integer timestamp for precise event sequencing.
bid_price	Highest available buy price at the top of the order book.
bid_size	Number of shares available at the top-of-book bid price.
ask_price	Lowest available sell price at the top of the order book.
ask_size	Number of shares available at the top-of-book ask price.
is_pre_post_market_session	Indicates whether the quote occurred during extended-hours trading (true) or regular market hours (false).
is_symbol_available	Indicates whether the security is currently active and eligible for trading on IEX.

Together, these fields allow developers to reconstruct tick-level top-of-book histories, calculate prevailing bid-ask spreads, isolate extended-hours quotes, and measure available top-tier liquidity.

Available REST Endpoints

FinFeedAPI provides REST endpoints for retrieving historical top-of-book Level 1 quote updates for individual stock symbols on the IEX exchange. For alternative transport protocols and AI-driven workflows, Native IEX Level 1 Quotes are also accessible through JSON-RPC and the hosted FinFeedAPI MCP Server.

Get Level-1 Quotes

Returns historical Native IEX Level 1 top-of-book quote updates for a specific stock symbol. The dataset contains tick-level bid/ask changes and session state flags throughout a trading day. If no date parameter is supplied, the latest available trading day is returned.

Response includes

bid and ask prices with corresponding share sizes
nanosecond timestamp and ISO 8601 UTC timestamp
pre/post-market session indicator
symbol availability flag

Requires an API key passed via the Authorization header (or X-APIKey). Accepts path parameter symbol (e.g., AAPL) and optional query parameter date formatted as YYYY-MM-DD (or ISO 8601 UTC string).

MCP & JSON-RPC Support

Native IEX Level 1 Quotes are accessible through multiple protocol interfaces beyond standard REST.

MCP Server

The hosted FinFeedAPI Stock Historical MCP Server exposes Native IEX Level 1 Quotes as a self-describing tool (stock_native_iex_level1_quotes), allowing AI agents, LLMs, and MCP-compatible clients (e.g., Cursor, Claude Desktop) to retrieve top-of-book quotes using the X-APIKey header.

Discovery and query workflow

1Discover supported exchanges with stock_exchanges_list.
2Retrieve symbols for the exchange with stock_symbols_list.
3Query top-of-book quotes using stock_native_iex_level1_quotes by providing symbol, date, and an optional limit.

If no quote data exists for the selected symbol and trading date, the MCP server returns an explicit error message instead of a partial payload.

JSON-RPC

Developers using JSON-RPC can access Native IEX Level 1 Quotes via the production proxy.

JSON-RPC acts as a thin transport wrapper over the REST API. The request sets method to v1/native/iex/level1-quote/{symbol} and passes symbol and date within params. The proxy forwards the request to the underlying REST endpoint while retaining identical authentication, parameters, and response structures.

Dataset Characteristics

Historical Native IEX top-of-book quote data
Available through REST API, JSON-RPC proxy, and hosted MCP Server
API key authentication required (Authorization header or apikey query parameter)
Single-symbol retrieval per request
Optional trading date parameter (defaults to latest available trading date)
ISO 8601 UTC timestamp formatting
Nanosecond timestamp precision (timestamp_nanos)
Raw top-of-book pricing and quote size attributes (bid_price, bid_size, ask_price, ask_size)
Boolean session status flags (is_pre_post_market_session, is_symbol_available)
Explicit error responses for invalid or empty symbol/date combinations

Why Developers Use Native IEX Level 1 Quotes Instead of Other Datasets

Both datasets record market activity, but they serve different operational purposes.

If you need...	Use...
Prevailing bid and ask prices at the top of the book	Native IEX Level 1 Quotes
Real-time top-of-book spread and depth calculations	Native IEX Level 1 Quotes
Extended-hours top-of-book price discovery	Native IEX Level 1 Quotes
Trade execution pricing and trade break detection	Native IEX Trades
Multi-tier order book depth beyond the top price	Native IEX Level 2 Price Levels
Full order lifecycle management (adds, modifies, cancels)	Native IEX Level 3 Order Book
Exchange-wide operational markers and session open/close boundaries	Native IEX System Events
Standardized historical candlestick charting	OHLCV Historical Data

Many production systems combine these datasets. Quantitative workflows often rely on Level 1 Quotes to evaluate top-of-book liquidity and benchmark trade execution pricing against Level 3 Order Books or tick-level Trades.

Common Use Cases

Calculate historical top-of-book bid-ask spreads and quote stability metrics
Benchmark order execution quality against prevailing top-of-book prices at fill time
Analyze liquidity distribution and quote sizes outside regular market hours
Measure price impact and quote re-pricing latency following market trades
Reconstruct historical BBO snapshots for backtesting routing logic

Who Uses This Dataset?

Quantitative Trading & Execution Teams
Market Making & Liquidity Providers
Financial Analytics Platforms
Algorithmic Strategy Developers
Academic & Market Microstructure Researchers

Native IEX Quotes

Explore Native IEX Level 1 Quotes Data

Native IEX Level 1 Quotes supply top-of-book pricing updates direct from the Investors Exchange, delivering the raw quote detail and nanosecond precision required for spread evaluation, BBO tracking, and execution benchmarking.

The dataset integrates naturally with the broader FinFeedAPI Stock ecosystem, including Metadata endpoints for venue lookup, Native IEX Trades, Level 2 Price Levels, Level 3 Order Books, Admin Messages, System Events, OHLCV timeseries datasets, and the hosted Stock Historical MCP Server.