Polygon.io serves both professional and non-professional users. However, there are a few differences between the two statuses. The U.S. exchanges require us to collect and maintain personal and employment information for all Stock API data recipients. The professional status is determined once you sign up on the website and complete a small list of questions. The data is the same for each, however exchange fees are much higher for professional users which is the reason for the price difference. The fees charged are regulated by the SIPs and required to remain compliant.
Learn more about non-professional and professional subscriber status on Polygon.io’s blog post - Understanding Professional Status. Professional users can find pricing by visiting our Enterprise Stock APIs page, or by using our Pricing Calculator to see what exchange fees are incurred from each enterprise package.