Massive (formerly Polygon.io)
Real-time and historical market data for stocks, options, forex, and crypto over low-latency websockets.
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Overview
Massive provides market data for US equities, options, forex, and crypto. The company was previously called Polygon.io and rebranded in October 2025, so older documentation and sample code still use the former name.
Historical data is available down to tick level over REST; live trades and quotes stream over WebSocket. Coverage includes options chains with Greeks, corporate actions, and company reference data. Real-time US equity access depends on exchange agreements attached to the subscription tier.
Common use cases
- Backfill historical price bars for a backtest
- Stream live trades and quotes into a chart
- Pull options chains with Greeks
- Fetch company reference and corporate action data
Key Features
- Real-time and historical stock, option, forex, and crypto data
- WebSocket streaming feeds with sub-20ms latency via direct exchange connections
- REST API for intraday, daily, and tick-level data
- SEC financials, news, and reference data endpoints
- Options chains with Greeks and implied volatility
- Forex and crypto aggregated from multiple exchanges
- Tiered pricing from free to enterprise with dedicated support
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