The chances of a financial collapse that could shake the world are slim. The Chinese government has vast sums of money it can tap in the event of a crisis. And there are steep financial barriers to keep money from fleeing the country. While investors have ways around the barriers, they limit the possibility that such a flight could bring one of the world’s most important growth engines to a halt.

Nevertheless, China faces some increasingly serious economic challenges. It is trying to tackle its considerable debt problems without starving its economy of the money that keeps growth chugging along. The president’s tariffs so far have been quite small in the grand scheme of things, but they add to China’s troubles. The next wave of tariffs, set at 25 percent, threatens to cover at least a tenth of China’s exports to the United States, and more could follow.

China’s stock markets reflect the uncertainty. The Chinese stock market as of this week is down more than 20 percent from its January peak, making it a bear market. The country’s main stock index lost nearly 1 percent on Thursday.

“You don’t know what Trump is going to do next,” said Hong Hao, the chief market strategist in the international unit of the Bank of Communications, one of China’s biggest banks. “Normally at this level, there should be a technical rebound.”

China’s moves with its currency reflect its difficult balancing act. The Chinese central bank has guided the currency steadily lower against the dollar, particularly in the past two weeks, as the likelihood of further American tariffs on Chinese goods has increased. The currency is down more than 5 percent from its peak in February.