Wall Street advanced sharply today, with solid preliminary results from IBM encouraging investors to go back into the stock market after last week’s rout.

Wall Street took an expected break from a week of frenetic buying today, leaving the major indexes mixed as investors bought blue chips but sold technology shares on an earnings warning from Nokia.

The Dow Jones industrials and the Standard & Poor’s 500 index notched a fourth straight week of advances after a day of mixed trading today, when optimistic investors started to wonder whether stock prices were getting a bit high.

Better-than-expected profits from Motorola lifted Wall Street higher today as investors grew more optimistic that third-quarter earnings in general will be strong. The Dow Jones industrials rose nearly 90 points to a 16-month high.

New worries about terrorism and another disappointing tech outlook sent US stocks falling sharply for a second straight session today, with technology stocks and the Nasdaq composite index bearing the brunt of the selling.