Trading on Chinese stock markets was halted for the day on Thursday just 30 minutes after the start of trading.
Trading was suspended for 15 minutes after the CSI 300 stock index fell 5%. When trading resumed, the slide continued and within just a few seconds the index was down 7%.
The abrupt decline triggered so-called circuit breakers, which Chinese authorities recently implemented in a bid to tame the country’s volatile markets.
It’s the second time in four days that China’s new circuit breakers have been used.
Persistent signs that growth in China — the world’s second largest economy — is slowing have spooked investors in China and around the globe.
Two separate reports this week fanned the fears. One showed that China’s services sector grew at the weakest pace in 17 months in December — another report revealed that the country’s key factory sector had contracted.
Another concern is China’s weakening currency: The yuan has lost about 1% this year against the dollar.
Concerns about what a slowing China means for oil demand have helped ravage oil prices — a trend that in turn hurts global economies and further unsettles stocks.
U.S. markets on Wednesday experienced another mini panic attack after North Korea claimed to successfully test a hydrogen bomb. Oil prices plunged below $34 a barrel — the lowest settle since 2008.
The Dow dropped 252 points, marking its worst start to a trading year through three days since 2008.
Most investing professionals recently surveyed by CNNMoney listed China as the biggest risk to U.S. stocks. When Chinese markets were halted Monday, the move triggered a global selloff, including losses of roughly 2% in the U.S.
Chinese markets had stabilized in the final months of 2015 after a summer crash caused trillions of dollars in losses.
Beijing reacted forcefully to that slide. The People’s Bank of China cut interest rates and regulators suspended new share listings and threatened to jail short sellers, or traders who bet that stocks will fall.
In an effort to prop up the market, regulators organized the purchase of shares using cash supplied by the central bank.
The Chinese government spent at least 1.5 trillion yuan ($236 billion) on the 2015 market bailout, according to analysis by Goldman Sachs.