Polygon.io
Market data API covering US equities, options, forex and crypto, with aggregates, trades, quotes, and websocket streaming on published tiers.
What it is good at
Published pricing and published limits. You can size a project against it before writing a line of code, which is rarer than it should be.
Scored against the five published criteria, identically for every entry, by the editors of this site. Scores are never sold and are not affected by any commercial relationship. Read the method.
What to watch
Coverage depth varies by asset class. Verify the specific instruments and history depth you need before designing around it.
This section is not optional and is not negotiable. Every entry in the register carries one, whatever the commercial relationship.
Access it
No commercial relationship. Polygon.io is listed on editorial merit and has no input into this description or its scores.