The rollercoaster ride continued on Wall Street Tuesday, with the bottom falling out from under investors by the end of the session.

There were fresh signs that global credit markets are seizing up, after Sentinel Management Group told investors to stop withdrawing cash to avoid forced liquidation. A lower profit forecast from Wal-Mart Stores renewed worries about consumer spending.

Economic news from the Labor Department drove the market at first. The Producer Price Index advanced a lower-than-expected 0.1 per cent in July, once food and energy was taken out of the equation. But once investors took a closer look at the numbers they began to worry about the upcoming consumer price index, considering the overall PPI rose an unexpected 0.6 per cent.

Separately, a Commerce Department reported the nation's trade gap fell unexpectedly in June. Imports outstripped exports by $58.1 billion as strong exports offset higher oil prices and a rise in imports from China