The Nasdaq composite index rose 98.34 to 4,267.56, and the Standard & Poor's 500 index added 13.94 to 1,501.34. The Dow Jones industrial average rose 80.35 to close at 11,114.27, led by Wal-Mart and Hewlett-Packard.
The CNET tech index gained 55.51 to 3,246.19, led by shares of VeriSign and National Semiconductor.
Winners beat losers, with 70 of the 98 stocks in the index rising and 28 falling.
Of the 18 sectors tracked, computer memory storage, semiconductor equipment, e-tailers and wireless companies posted the sharpest gains with each rising 5 percent. PC hardware makers were the day's largest losers, falling a slim 0.4 percent.
Intel fell 6 cents to $129.81, while Microsoft inched down 38 cents to $86. The Justice Department will defend its prosecution of Microsoft as a monopoly in a routine hearing in Congress. Sun Microsystems said it is considering filing another antitrust lawsuit against the Redmond, Wash.-based software giant.
Shares of QXL.com, a European online auction house, more than doubled this morning to become the largest percentage gainer on the Nasdaq Stock Market. The company rose $51.98, or 132 percent, to $29.66 on a volume of 14 million shares, more than 96 times its average daily volume. SG Cowen started coverage on the stock with a "strong buy" rating and set a $333 price target.
The North Face, an outdoor clothing company, was the Nasdaq's largest loser, falling $1.22, or 67 percent, to $2.47 on a volume of 4.3 million shares, more than 15 times its average volume. The company announced difficulties that left doubt about its ability to continue as a going concern.
Among members of the CNET tech index, VeriSign and National Semi posted strong gains.
VeriSign rose $24.88, or 19 percent, to $155.25 after receiving favorable comments from analysts.
National Semi rose $6.44, or 11 percent, to $64.56 along with other semiconductor companies on news of strong worldwide sales.
The Philadelphia semiconductor index rose 21.81 to 1,156.57, led by National Semi and Teradyne, which gained $9, or 10 percent, to $96.
Yahoo fell $11.56 to $154. The Internet portal reported earnings that slightly surpassed analyst expectations after the markets closed yesterday.
Peregrine Systems fell $21.25, or 36 percent, to $36.75 on concern that the business-software maker's planned $2.1 billion acquisition of Harbinger could slow growth. Harbinger rose $2.44, or 10 percent, to $26.56.