Stocks End Volatile Day With Gains

Updated from 3:30 p.m. EST

Stocks on Wall Street rocked higher and lower Tuesday, as traders weighed encouraging news from several big technology companies against troubles in the financial sector and the automakers' group.

But in the end, the major indices racked up gains. The Dow Jones Industrial Average ended up 151.17 points, or 1.8%, at 8424.75. The S&P 500 gained 8.36 points, or 1%, at 859.11. The Nasdaq tacked on 1.22 points, or about 0.1%, at 1483.27.

Two pieces of news provided an initial lift to technology shares. Computer hardware and software maker Hewlett-Packard (HPQ Quote) was partly responsible, after the company said its fourth-quarter profit would exceed analysts' expectations. Shares of H-P, part of the Dow, rose 14.1% to $33.48.

Charles Rotblut, senior market analyst at Zacks Investment Research, said that H-P's earnings beat "actually was a very big surprise." He said that eight analysts had cut their quarterly forecasts in the past month, including five in the last week.

However, "It does seem like it's a bit of an outlier, given everything else we're seeing going on," said Rotblut. "Based on the economic trends we're seeing, I really don't have a very optimistic view for the technology sector in the short term."

Another boost came from Yahoo! (YHOO Quote), which said CEO Jerry Yang is set to step down from his position as soon as the Internet firm can find a replacement. Yang's tenure was recently marked by a refusal to sell his company to Microsoft (MSFT Quote). Yahoo! shares were likewise rose 6.7% to $11.34.

Financial firms continued to look weak as the new session arrived. Asset manager BlackRock (BLK Quote) joined the set of companies to announce layoffs by announcing its first round of job cuts in its 20-year history, according to a report by Bloomberg.