Chinese Market Has Shortest Trading Day In Its 25-Year History

U.S. markets are volatile Thursday morning, after the Chinese stock market was halted for a second time this week. This latest halt, which occurred about 30 minutes after the opening, led to the shortest trading day in the 25-year history of the China market.

The Shanghai Composite ended its day down 7 percent. The Wall Street Journal said the halt was due to "Beijing's growing tolerance of a weaker currency intensified concerns about capital flight and the health of the world's No. 2 economy."

In other world markets, Japan's Nikkei 225 was down more than 2 percent, while the Hang Seng Index was down just a tick over 3 percent. The Stoxx Europe 600 was down 3.4 percent, while Germany’s DAX index fell 3.5 percent.

S&P 500 futures were taking a hit on the news. The SPDR S&P 500 ETF Trust SPY was trading down about 2 percent in Thursday's pre-market session.

"Traders and analysts said that the weakening of the yuan in the morning triggered the initial losses, which spilled into the rest of the region. The yuan's [also known as the renminbi] weakening raises the likelihood of capital flight and currency depreciation in neighboring economies," according to MarketWatch.

This was the yaun's biggest fall in five months.

The New York Times noted: "China's currency, the renminbi, continues to be a sore spot, and the Chinese central bank on Thursday once again intervened. The Chinese government...has been allowing the value of the currency to decline steadily. It is a difficult process to manage, especially as companies and individuals send money out of the country at a rapid rate."

Daniel So, strategist at CMB International Securities, told CNBC that, "For now the [People's Bank of China] will be comfortable to see the currency weaken further to help the economy," he said, adding that further depreciation, however, may eventually push the bank to intervene again."

Earlier this week, Apple Inc. AAPL fell after concerns about iPhone sales in the Chinese and Asian markets. The stock ticked under $100 on Wednesday afternoon, the first time it was under triple digits since the August 2015 Flash Crash. Shares were down 2.7 percent at $97.91 in Thursday's pre-market session.