In brief
- Stocks on China’s mainland have lost about $2.4 trillion in market value since May, and the STAR 50 index of tech and chip companies is down 40% in under four months.
- AI companies make up 42% of the market value of Chinese shares and 57% of trading, according to Goldman Sachs, while U.S. curbs now target Chinese robots and data center parts.
- Brent crude above $111 and 10-year Treasury yields near 5% are pressuring risk assets worldwide, with Bitcoin briefly under $80,000 ahead of the Fed’s October 28 decision.
Stocks on China’s mainland have lost about $2.4 trillion in market value, the total worth of all their shares, since May, as investors lose faith that Beijing’s AI boom will ever turn a profit.
That is more than South Korea’s entire economy produces in a year.
AI companies now make up 42% of the market value of Chinese shares listed on the mainland and in Hong Kong, and 57% of trading, according to Goldman Sachs. So when AI stocks fall, the whole market falls with them.
The CSI 300, an index of China’s 300 biggest listed companies, entered a bear market on October 22, meaning a drop of at least 20% from its peak.
The sharpest damage hit Shanghai’s STAR 50, an index of 50 large tech and chip companies. It fell 40% in less than four months, erasing about $480 billion.
It still trades at roughly 100 times earnings, a ratio that shows how many years of current profit investors are paying for, down from nearly 250 at its peak. The Nasdaq 100, the U.S. tech benchmark, sits around 30.
DeepSeek, a Chinese startup, released a cheap and powerful chatbot in January 2025, and Nvidia, the U.S. company whose chips power most AI, lost nearly $600 billion in market value in a single day. Moonshot AI’s Kimi K3, also produced by a Chinese AI lab, sent chip stocks tumbling again in July.
Beijing then pushed its tech giants toward homegrown chips: According to the Financial Times, its internet regulator reportedly told companies including ByteDance and Alibaba to stop buying Nvidia chips in September 2025. Z.ai, a Beijing lab, says it trained its GLM-5.2 model entirely on Huawei chips.
Analysts blame weak spending by Chinese consumers and doubts that AI companies can earn back what they have invested. Robot maker Unitree drew retail orders for 8,000 times the shares on offer when it listed in August, and its stock has since lost almost half its value since launch even after a significant recovery this week.
“The stock market later evolved into a speculative crazy bull,” said Dong Baozhen, a Beijing-based fund manager. “And now we see the bubble bursting.”
The U.S. Federal Communications Commission banned imports of new foreign-made humanoid robots in July on national security grounds. Washington is also moving to ban Chinese-made optical parts from U.S. data centers, and the makers Zhongji Innolight and Eoptolink are down about 60% from their peaks.
