"Risk appetite is going to evaporate in the coming days. How long that risk-off will go remains the question," says William Hobbs, head of investment strategy at the wealth management unit of Barclays in London.
U.S. stocks joined a rout that has global equities poised to enter a bear market, as investors ignored Janet Yellen's signal that the Federal Reserve won't rush to raise rates in the face of market turmoil.
U.S. Treasuries gained with emerging-market assets as futures traders held to bets that the Federal Reserve wont raise interest rates this week amid ongoing financial- market volatility. Stocks struggled for direction after their biggest weekly advance since July.