Until Uber passed it in July, Xiaomi was the world’s most highly valued startup, at $46 billion. Wait—a Chinese smartphone company worth what? Lei Jun and Xiaomi have spent the better part of this year explaining why that optimism is justified. It’s about more than just phones. The company has so far invested in a couple dozen device companies—with plans to fund at least 100—selling air purifiers, GoPro-like cameras, and hi-fi headphones in a bid to create an ecosystem that will replicate the success of Apple’s universe. Xiaomi’s backers say it makes money selling phones. But Xiaomi is trying to prove to skeptics that it can do much more.