If you don’t care about price, and want to hammer the data provider with as many API calls as you can muster, thenXigniteis 100% where you should look.
With customers likeWealthfrontandRobinhood, they have already made themselves a name in the community. Boasting one of the largest selections of data packages, (pay is per package per region), these guys don’t have an API limit.
Similar to Intrinio in the payment scheme, they differentiate themselves by focusing in on the commercial application market. They pride themselves on being possibly the best in terms of technical infrastructure. They have a 7-day limited trial program, that doesn’t really do them justice. They use a data-as-a-service model where you get their data down from the AWS cloud.
Another company with strong human interaction, they have a sales team that makes sure customers feel taken care of and supported.
The downside of these guys is price. A comparable package from Intrinio can cost maybe more than five times as much on Xignite’s platform.
Here’s Patrick's lineup for Best Overall Stock Market APIs