The bursting of China’s tech bubble has long been deemed unlikely by bulls who argue that the country’s massive population and substantial national support for the sector would spare startups from the same fate that befell American tech companies in the early 2000s. But the latest figures from China’s tech sector suggest that caution is necessary.

Venture capital (VC) deals in Greater China (which includes both Taiwan and Hong Kong) plunged both in terms of volume and value in the first half of this year. According to data from market research firm Preqin, 1,375 VC deals successfully closed during the period this year, compared with 2,593 a year ago, an almost 50% decrease. Meanwhile, the value of deals fell 66% from $59.2 billion in the first half of last year to $19.9 billion in the same period this year.

The largest deal in the first six months of 2019 was a $1 billion fundraising by e-commerce giant JD.com’s health care subsidiary, according to Preqin.

That marks an end of a remarkable bull-run in China’s VC sector, which saw deal value increase from $17.6 billion in 2014 to $105.7 billion in 2018—a year that included a $14 billion fundraising round by Ant Financial, the payments arm of Alibaba. The abundance of investment helped fuel the emergence of multi-billion-dollar Chinese unicorns like ByteDance, the parent company of video app TikTok, which is said to be valued at $75 billion.

Uncertainties such as the trade war between China and the US and the lackluster performance of tech companies in the stock market have weighed on investor sentiment. Shares of Hong Kong-listed smartphone maker Xiaomi, for example, have lost more than 50% in value since it went public in July last year.

The poor performance in China’s VC sector so far this year suggests that the era of exuberance in the sector might be coming to an end. As such, many Chinese startups could be at risk of seeing their valuations plummet, or shutting down entirely.

“There has been a mismatch between the high valuations of private startups and the falling share prices of some listed tech firms, leaving room for the formation of a bubble in the sector,” said Peter Mao, a partner at Chinese VC firm Panda Capital. “Investors in China now tend to be really cautious.”