Bloomberg reported rising alarm from business leaders over President Donald Trump’s threats to ban business with China, with Business Roundtable President and CEO Josh Bolton warning the on-going trade war could depress new investments.

According to Bloomberg, concerns were raised by business leaders in the wake of Trump’s tweets on Friday, when he suggested he would use the International Emergency Economic Powers Act of 1977 to block U.S. companies from doing business with China.

The Dow Jones Industrial Average experienced a 623-point drop in the wake of the tweets.