HONG KONG/SINGAPORE -- In early October, as investors were dumping stocks in emerging markets from China to Argentina, veteran Wall Street investor Byron Wien sent out a memo to his clients. "The major question confronting investors is whether the U.S. equity market can continue to move higher when the rest of the world is experiencing an economic slowdown, political turmoil and trade disputes," Wien, vice chairman of the Blackstone Group, wrote.
He cited past examples when U.S. investors remained calm even as emerging markets collapsed around them. But then he introduced a note of caution. "If the economies of Europe and particularly China weaken seriously, that could have an impact" on American stocks.