Stocks mostly fell on Wednesday.
The S&P 500 fell 0.6 percent to return to negative territory for 2016.
The STOXX Europe 600 fell 0.1 percent, giving up gains earlier in the day.
Asian stocks were mixed. The Shanghai Composite Index rose 0.4 percent but the Nikkei 225 fell 0.3 percent.
Stocks were dragged down by oil. West Texas Intermediate crude plunged 4 percent while Brent tumbled 3.2 percent.
“Investors are questioning this explosive near-term rally off February lows, which left stocks in an overbought condition,” said Channing Smith, portfolio manager at Capital Advisors. Smith added that “economic data seem hollow, nothing to suggest acceleration”.