Apple Inc. invested $1 billion in China-based ride-sharing firm Didi Chuxing, formerly known as Didi Kuaidi. The firm ranks as the second-largest company in a workforce segment that Staffing Industry Analysts defines as the human cloud. The largest is Uber.

“Didi exemplifies the innovation taking place in the iOS developer community in China,” Apple CEO Tim Cook said in a statement. “We are extremely impressed by the business they’ve built and their excellent leadership team, and we look forward to supporting them as they grow.”

Apple’s investment represents the largest single investment the company has received.

Didi Chuxing completes more than 11 million rides per day on its platform, according to the company. It also a rival to Uber in China. Reuters reported earlier this year that Uber’s China business received almost $2 billion in funding from Chinese investors, and in a separate report indicated Uber was losing $1 billion a year in China.

Last September, Didi Chuxing invested $100 million in US-based ride-sharing firm Lyft.

Didi Chuxing took on the new name last September.

Meanwhile, this week Lyft reported it is on a path to profitability.