Polygon (Massive) vs Databento

Polygon.io (now Massive.com after October 2025) and Databento are both high-quality market data APIs, but they serve different use cases. Polygon is a normalized data provider: it cleans, aggregates, and delivers OHLCV bars, real-time quotes, and options chains primarily for US equities, options, and crypto. Databento is a raw exchange feed provider: it delivers original venue data in exchange-native schemas from 70+ venues worldwide, with a strong focus on futures and microstructure. Choosing between them depends on the granularity you need and the asset class you are researching. No investment advice, no affiliate links — neutral comparisons for researchers choosing their stack.

Head-to-Head Comparison

Prices marked [approx] were behind signup walls at time of research; re-verify at the provider's current pricing page before committing. Polygon rebranded to Massive on October 30, 2025; api.polygon.io still works in parallel.

Five Points of Nuance

1. Polygon = Massive.com now — what changed and what did not

Polygon.io rebranded to Massive.com on October 30, 2025. The underlying data product, team, and API are unchanged. The old api.polygon.io endpoint continues to work in parallel during the transition. Pricing and plan documentation now live at massive.com, and plans are split by asset class (equities, options, FX, crypto) rather than a single unified subscription. If you have existing code using the polygon-api-client Python SDK, it should continue functioning; check the Massive SDK page for any updated client packages as the migration matures.

2. Normalized data vs raw exchange feed — the fundamental distinction

Polygon cleans, normalizes, and delivers market data in standard formats: OHLCV bars, quotes, trades, options chains, indices. The normalization layer handles corporate actions, exchange quirks, and schema differences across venues. Databento delivers data in the original schemas used by each exchange (CME MDP 3.0, ITCH, PITCH, and others), including raw order-book depth (Market-By-Order, level 3). This is the closest to what institutional quants receive from direct exchange feeds. The trade-off: Polygon is easier to consume immediately; Databento requires more data engineering but gives you the highest-fidelity raw input for microstructure research, transaction cost analysis, and strategies where fill model accuracy depends on order book state.

3. Asset class coverage: Polygon for US equity breadth; Databento for futures depth

Polygon's primary strength is US equities and options: broad coverage, tick-level and minute-level history, options chains, and indices. It also covers crypto and FX. Databento's primary strength is futures: CME, ICE, Eurex, and 70+ additional venues with continuous contract data, roll adjustments, and tick-level order book history going back 15+ years for major contracts. Both cover equities, but their depth and schema differ. For a researcher focused on US stock mean reversion or momentum on intraday data, Polygon is the more natural fit. For a researcher building a trend-following strategy on diversified futures, Databento is more appropriate.

4. Free tier structure: ongoing rate limit (Polygon) vs credit-based trial (Databento)

Polygon's free tier is ongoing: 5 requests per minute with delayed data, no expiration. This is useful for prototyping code, testing API integration, and small historical pulls where rate limits are acceptable. Databento's entry point is $125 in data credits valid for 6 months — enough to pull tick data for a specific futures contract or equity sample for a research project. After those credits are exhausted, Databento charges pay-per-GB or a flat subscription. There is no ongoing free rate-limited tier. For sustained free access to market data for learning or lightweight backtesting, Polygon's free tier is more practical. For a focused research project that needs real tick data, Databento's credits cover a meaningful amount of historical data.

5. Survivorship bias: neither is explicitly bias-free

Neither Polygon nor Databento is marketed as a survivorship-bias-free provider in the way Norgate Data is. Polygon includes delisted symbols in its historical data files, which provides partial bias protection for equity backtests. Databento delivers raw exchange feeds that include all historical instruments traded on those venues, including contracts that have expired or been discontinued — which is as close to bias-free as raw data allows. Neither, however, provides the explicit survivorship-bias-free guarantee and point-in-time corporate action adjustment that equity factor researchers need for rigorous cross-sectional work. For that use case, Norgate Data (EOD only) remains the only explicitly marketed bias-free source in the retail space.

Best for Whom

• US equities, options, and crypto intraday research: Polygon/Massive. Broad normalized coverage, easy REST API, ongoing free tier for prototyping, active development post-rebrand.
• Futures research and microstructure: Databento. Raw exchange feeds from CME, ICE, Eurex, and 70+ venues; tick-level order book; continuous contract history; closest to institutional-quality data at retail pricing.
• Migrating from IEX Cloud (equities): Polygon/Massive for the most direct intraday US equity replacement; Tiingo for a cost-effective alternative; Databento for tick-level upgrade.
• Transaction cost analysis (TCA): Databento. Level 3 order book data from exchange-native schemas is the appropriate input for realistic fill modeling and implementation shortfall analysis.

When Neither Fits

For survivorship-bias-free equity backtesting with explicit EOD history of delisted symbols, Norgate Data is the only provider in this comparison space that explicitly markets this guarantee — but it is EOD only, with no intraday data. For free learning and prototyping where ToS risk is acceptable, yfinance (daily prices, no key) is the most widely used starting point. For broader coverage of US fundamentals, alternative data, and international equities at lower price points, Tiingo (~$10/mo), Alpha Vantage (25 req/day free), Finnhub (60 req/min free), and EODHD ($0–$100/mo) fill niches that neither Polygon nor Databento covers as cost-effectively.