Updated from 4:10 p.m. EDT

Stocks plunged to their lows of the month Thursday despite a small face-saving rally at the end of the session. A combination of uncertainties about the economy kept buyers on the sidelines after a mixed report on economic growth, while the barrage of first-quarter earnings releases continued to glow.

The Nasdaq Composite continued to lead the slide, shedding 30.76 points, or 1.55%, to 1958.78. The Dow Jones Industrial Average was down 70.33 points, or 0.68%, to 10,272.27, and the S&P 500 was down 8.53 points, or 0.76%, to 1113.88. The 10-year Treasury bond was trading down 8/32 in price to yield 4.53%, while the dollar was lower against the yen and the euro.

In heavy trading, volume on the New York Stock Exchange exceeded 1.8 billion, while nearly 2.4 billion shares changed hands on the Nasdaq. Decliners outnumbered advancers by about 7 to 2 on both markets.

"We've been going down for a full week here, and the pattern is pretty clear that selling keeps re-emerging in the afternoons," said Joe Liro, equity strategist at Stone & McCarthy Research Associates. "No one wants to carry a position overnight, and that really shows that there's a lack of conviction here to hold things up for very long.

"If we don't get a clear catalyst to push us back towards the top of this range, then I'm going to have to rethink what has been my bullish outlook on the market if we don't see an improvement over the next couple of weeks," he added.

The Nasdaq broke through its April low, an important support level, at around 1978, according to Ken Tower, chief market strategist at Cybertrader. He thinks the index has further to fall. "Now, we have the 200-day moving average that we're coming down to on the Nasdaq at about 1932, and the other probably stronger support area for the Nasdaq is the March lows around 1900," he said. "The S&P is also breaking down below its April 20 low. The Dow is the only major index clinging to that level.