The Shanghai Composite Index, which consists of all 1,583 stocks traded on the bourse, plummeted over 9% at the beginning of the trading on Monday, and later recovered some of the losses to shed over 8%. Its smaller peer, the Shenzhen Component Index, which tracks the performance of 500 major stocks listed on the exchange, also shed over 8% as of Monday noon.

More than 3,000 stocks, or over 80% of all Chinese shares listed on the country’s two major stock exchanges in Shanghai and Shenzhen, saw trading suspended (link in Chinese) after they sank heavily, hitting China’s daily limit that caps gains and losses to 10%. Monday’s morning trading marked the worst fall in Chinese markets since 2015, when China saw more than $2.7 trillion in value wiped from the markets in less than a month as investors pulled out after speculative buying, some of it using borrowed money, had sent prices to impossible levels.

China’s new coronavirus, which has spread globally, poses an enormous challenge to an already slowing Chinese economy. Already, Lunar New Year travel has been hit, with more than than a dozen Chinese cities on lockdown. Domestic consumption has also plunged, with movie theaters, amusement parks, and cafes shut down, and people staying home out of fear of infection. Small businesses and farmers will suffer too, while factories—even those making emergency supplies—could face staff shortages if some people decide to stay home in their villages even after the break, which was extended to Feb. 2 by Beijing to contain the spread of the virus.

Meanwhile, the markets plunge will weigh heavily on the country’s over 150 million retail investors, who account for the majority of China’s stock investors, compared with the US where institutions are the major investors.

China is also far more embedded in the global economy than it was during the SARS outbreak in 2002-2003 and the economic turmoil from this epidemic is likely to be felt far beyond its borders. The US, Australia, and Singapore, among others, have banned entry to travelers who have been to China in the past 14 days, and airlines have suspended service. In mainland China, multinationals like Starbucks and Apple have closed stores, while Tesla shut its new Shanghai Gigafactory on government orders, a move it said it expected to see reflected in its financials.

📬 Sign up for the Daily Brief

Our free, fast, and fun briefing on the global economy, delivered every weekday morning.