Wall Street off session lows as Apple reverses course

The stock gave the biggest boost to the Dow, S&P 500 and the Nasdaq, helping the U.S. markets cut their losses. The Dow fell to a six-month low earlier in the day, while the Nasdaq and the S&P hit a one-month low in a broad decline, with the S&P even briefly turning negative for the year. The CBOE Volatility index , a measure of the premium traders are willing to pay for protection against a drop in the S&P 500, jumped as much as 18.7 percent to 16.28, its highest level in a mont