In 2010, almost every new billion dollar company that entered the market called US or Europe home. Times are changing.

China is now closing the gap with the US (and rocketed past Europe in 2015) when it comes to minting new $1 billion startups, reports the investment advisory firm Scenic Advisement which analyzed financing data from CB Insights.

So far this year, 12 of the 33 such companies created around the world are in China. That’s the latest milestone in a long-term trend. More than a quarter of new unicorns have been created in China since 2010. The rise comes as a flood of private capital has lifted startup valuations around the world, and China’s economy begins to mature (paywall) into a more advanced service economy.

It’s too soon to know the “true” value of many of these companies. While flush with venture capital, only a few have faced the scrutiny of public investors.

But the trend is clear. The number of new billion-dollar startups in China is now tracking their counterparts in the US quite closely: 34 unicorns have arrived in China since mid- 2015 compared to 39 in the US. Although the US still holds an advantage in the total number of such companies (it’s home to 100 unicorns created in the US since 2010, compared to 56 in China), the advantage may fade.

That bi-polar world has already arrived, says Duncan Logan, CEO of the global technology accelerator RocketSpace, citing Tencent (versus Google), Didi (versus Uber) and WeChat (versus Facebook). China has shown a willingness to shut out foreign competitors, and its economy has roared along with 7% GDP growth in recent years, compared to 1% to 2.5% growth in the US. The country is on track to become the world’s largest economy by 2030 or sooner. It also has an unrivaled set of local markets for startups: The US has 11 cities with more than a million people, while China has more than 100.

Silicon Valley remains the center of the world’s top technical talent, capital, and people willing to fund risky ideas, but soaring housing prices and salaries in the Bay Area are leading companies to leave for less expensive cities. Chinese nationals studying abroad are now returning to China in greater numbers, reports The San Francisco Chronicle, citing the hostile environment in the US and opportunities back home. Last year, 432,500 of this returning cohort, known in Chinese as haigui or sea turtles, made the trek back home, an increase of 58% over 2012.

“You’re starting to see serial entrepreneurs move out of the Valley and go to other cities and try to hire people and start up something elsewhere,” says Veronica Wu, managing director of Hone Capital who has helped set up operations for Motorola, Tesla, and Apple in China. “I definitely think it’s a threat, but right now [Silicon Valley] is still hard to replicate anywhere else.”

Correction: A previous version of this post referred to Hone Ventures. It is Hone Capital.