Expedia Group’s $21.5 million acquisition of Chicago-based ApartmentJet Inc. translates into a windfall for angel investors in Pittsburgh.

BlueTree Venture Fund and BlueTree Allied Angels will realize a 4.3 times return on its combined $450,000 investment in less than a year, said Catherine Mott, founder, CEO and managing partner of 15-year-old Wexford-based BlueTree Capital Group LLC.

“This is the quickest exit we have ever experienced,” Mott said.

The venture fund invested $150,000 in ApartmentJet last November and the angel group invested $300,000 in the young company in February, she said.

“On average, our previous profitable exits range with holding periods of four to six years,” Mott said. “The largest return historically for us is Wombat with a 12 times return.”

In February, Pittsburgh-based Wombat Security Technologies, a security awareness and training software firm, was acquired for $225 million by Proofpoint, a Silicon Valley cybersecurity company. BlueTree Allied Angels invested $266,500 in Wombat over a three-year period.

BlueTree Venture Fund has $10 million and BlueTree Allied Angels has $40 million under management.

ApartmentJet is a web-based platform to help multifamily property owners and management companies take advantage of the growing market for short-term rentals.

“Demand for short-term rentals in U.S. urban destinations has been growing impressively over the past several years,” Mark Okerstrom, Expedia (Nasdaq:EXPE) president and CEO, said in a prepared statement. “In order to be able to deliver our customers what they are asking for while at the same time promoting responsible renting, Expedia Group is committed to delivering solutions that give urban building owners, managers and communities control and transparency over short-term rentals.”