US stocks fall as bearish signs grow US stocks fell for a second day and the S&P 500 closed below a key technical level after disappointing forecasts from eBay and other companies, casting doubt on the market's recent strength. SPI futures are down 15 points at 4914 The Australian dollar is buying $US1.0302 The CBOE Volatility Index, Wall Street's fear index, gained 6.4 per cent to 17.56. The VIX is up roughly 46 per cent for the week so far. It still remains well below its recent highs, but the gains could signal a change in the market trend. Stocks have rallied for much of the year on views that the US economy is strengthening and the Federal Reserve will keep its economic stimulus in place. More recent data on the economy has been less upbeat. On Wednesday, reports showed factory activity in the Mid-Atlantic region cooled in April and the index of leading indicators, a gauge of future US economic activity, fell in March for the first time in seven months. The fact that it's a down day is not that surprising. We haven't had great economic news," said Karyn Cavanaugh, market strategist at ING Investment Management in Hartford, Connecticut. Volume was roughly 7.04 billion shares traded on the New York Stock Exchange, the Nasdaq and the NYSE MKT, compared with the average daily closing volume of about 6.36 billion this year. Volume has been heavier on negative days this week, as many investors have anticipated a pullback for some time after stocks' strong run to start the year, and are quick to book profits. The S&P 500's moving average was also the floor of the trading range during the last month, making 1,543 a key technical support, according to Richard Ross, global technical strategist at Auerbach Grayson in New York. Ross and others noted that the S&P 500 has posted negative second quarters in the last three years. The S&P 500's healthcare sector also experienced big declines, with UnitedHealth Group Inc down 3.8 per cent at $US59.69, after the insurer lowered its 2013 revenue outlook. S&P 500 earnings are now expected to have risen 1.9 per cent in the first quarter, up from the 1.5 per cent estimate at the start of the month, based on actual results from 82 companies and estimates for the rest, according to Thomson Reuters data. Of those that have reported, 72 per cent have topped analysts' expectations, but only 43.9 per cent have beaten revenue forecasts.