Another ‘unicorn’: Waltham data company Actifio is worth $1.3b

Actifio, a Waltham company that helps businesses store and manage large amounts of data, said Tuesday that it is now worth more than $1.3 billion, making the firm one of the most valuable startups in Massachusetts.

Actifio said it had raised $100 million in new funding from venture capitalists. The company collects clients’ data and stores a master copy that it says can be accessed by many different applications — reducing the complexity of systems that store multiple copies for different uses.

The announcement is the latest in a string of disclosures that have demonstrated just how much value is locked up in privately held Massachusetts firms. Last week, for instance the 3D printing company Formlabs said it had also become a “unicorn” startup worth more than $1 billion. And in July, the restaurant technology maker Toast said it had joined the billion-dollar club.