Important business data that is not known to the public is considered what type of information?

Answer: Insider Information

Confidential information that only individuals working in an organization know about the company is known as insider information.

This information is not usually disclosed to the public and a company's management team may or may not choose to make this information public at a later date.

Using such information to buy and sell shares of a company is usually considered illegal and is a punishable offence under law.