The story, "Wall Street Beat: Tech rides market optimism," posted Friday, omitted the time frame for the gains in the value of computer stocks noted in the second paragraph. In the fourth paragraph, the reference to the year was incorrect.

The second paragraph has been corrected on the wire and now reads:

Riding a wave of positive economic news, shares of computer companies on the Nasdaq closed Thursday up by 17.73 percent in aggregate for the year, better than any other sector on the exchange. Tech stocks are also up higher for the year in the Standard and Poor's 500, at 16 percent, than any other sector in the index. On Friday morning, tech stocks ticked up again, rising 10.14 points to 1633.36 on the Nasdaq.

The fourth paragraph now reads:

Much of the recent rise in share prices -- for tech as well as other sectors -- is due to general optimism stirred by positive economic news, after a very worrying year. In 2011, the possibility of a sovereign debt default by Greece and potentially other countries raised the specter of chaos in financial markets, sparking huge market swings and depressing stocks, including shares of tech companies.