IBM was at center stage of the day’s stock market rally, with its shares gaining almost 2.5 percent.

The stock rose $2.15, or 2.47 percent, to close at $89.10 for the day. Overall, the Dow Jones rose 83 points while the Nasdaq gained 30 points to reach an 18-month high.

IBM gained ground after Credit Suisse First Boston (CSFB) raised its investment rating on the computer maker. The firm upgraded IBM to an “outperform” rating from a “neutral.”

CSFB also lifted its 2004 profit estimate for IBM on the belief that it is the “ideal late-cycle technology spending recovery play.”

IBM is headquartered in Armonk, NY, and has its largest concentration of outside employees in RTP.