The Hang Seng China Enterprises Index closed down 7.2% to start the week, its largest one-day drop since November 2008, while the Shanghai Composite fell 2.6% and the Shenzhen Component dropped roughly 3.1%.

Tech stocks were under particular pressure in Chinese markets, as shares of Meituan cratered 16.8% on Monday while Tencent and Alibaba sank 9.8% and 10.9%, respectively.

In U.S. trading, Chinese ADRs struggled to start the week. Shares of e-commerce powerhouses Alibaba, JD.com, and the agriculture-focused Pinduoduo were all down well over 7% through mid-morning hours. Search-engine operator Baidu also fell as much as 14% in early morning trading before recovering some of its losses. 

The Golden Dragon China Index, which tracks American Depository Receipts (ADRs) of Chinese companies, is now down over 36% in the past month alone. And lockdown fears added to investors’ pain on Monday, as the index fell as much as 13%.

JPMorgan analysts also downgraded at least 10 Chinese internet stocks to sell-equivalent ratings on Monday, calling them “uninvestable” due to “rising geopolitical and macro risks.”

Another lockdown in mainland China

The fall for Chinese equities came after authorities in China’s tech hub Shenzhen ordered 17.5 million residents into a week-long lockdown on Sunday. Sixty-six new cases of COVID-19 brought the city’s total to over 400 since February, prompting action from health officials under China’s zero-COVID policy.

Shenzhen’s shutdown could cause major disruptions to international supply chains as the city boasts some of the world’s largest ports and plays a crucial role in connecting U.S. and Chinese businesses.

Investors and analysts fear a slowdown in economic growth due to lockdowns could translate to falling stock prices in the coming months as well. Analysts at ANZ Research wrote in a Monday note to clients that “if the lockdown is extended, China’s economic growth will be significantly affected,” CNBC reported.

The lockdown of Shenzhen has already led to problems for Apple as the firm’s largest supplier Foxconn was forced to shut two of its manufacturing sites on Sunday. 

Fears that Russia asked China for military aid

The broad rout in Chinese stocks also comes after reports that Russia has asked China for military assistance in its fight against Ukraine. Despite Chinese officials’ denials, investors fear that global backlash or even sanctions could be in the cards if China is seen to be undermining Western efforts to help Ukraine defend itself.

The sell-off in Chinese stocks shows how the war between Russia and Ukraine could have many far-reaching financial effects, especially when combined with a still-ongoing pandemic.

Beyond COVID-19 and Russia-Ukraine-related fears, regulatory risks in the U.S. have played a part in the latest downturn for Chinese stocks.

Last Thursday, the U.S. Securities and Exchange Commission revealed a spate of new Chinese companies subject to delisting under the Holding Foreign Companies Accountable Act as it continues to crack down on foreign firms that refuse to open their books to regulators.

Analysts predict the number of delistings of Chinese companies trading in the U.S. may only continue to rise over the next few weeks.

“The SEC identifies what companies are subject to delisting as early as the firm files its annual report and on a rolling basis,” Morningstar senior equity analyst Ivan Su writes told Forbes. “Therefore, we expect more Chinese ADRs to be included in the Provisional List over the next few weeks.”