Ring, founded in 2012, has raised more than $400 million in debt and equity sales, according to PitchBook data. Its most recent outside investment round, in October, raised $160 million and valued the company at $760 million.
Amazon’s Alexa Fund was among the company’s backers.
The Santa Monica, Calif., company is the second connected home security startup that Amazon acquired recently. The company in December acquired Blink, a Massachusetts-based maker of doorbells and cameras.