Tech companies appear to have learned from past

— -- If you're tempted by technology funds, you probably feel like Charlie Brown trying to kick a football held by Lucy Van Pelt. You'd like to believe that the tech rally won't get snatched away as soon as you invest. But you've been suckered too many times.

Still … the tech-rich Nasdaq stock index has soared 56% from its March lows, and it would be great to get some of those red-hot returns. Is it worth a shot?

Quite possibly. But before you tee up tech stocks, make sure that you don't have enough tech already.

The usual reason investors jump into technology is because it's been doing well lately. And that it has: Technology accounts for half of the S&P 500's gain since its bottom on March 9, says S&P senior analyst Howard Silverblatt. The sector now accounts for 18.8% of the Standard & Poor's 500-stock index, by far the largest sector weighting in the index. Energy, the next-largest sector, is 13.8% of the index.

Of course, those who follow red-hot performance often regret it. Anyone who bought tech in the 1990s is still seeing stars. The Nasdaq had an intraday peak of 5133 in March 2000; it closed Thursday at 1984, a 61% loss. Why invest in tech now?

One reason is that tech companies apparently have learned a few lessons from being treated like the stars of a decade-long Punch and Judy show. Companies that produce semiconductors, for example, were often the last to figure out when a recession hit. They were left with huge inventories of computer chips to sell at rapidly declining prices.

Not this time, says Zach Shafran, manager of Waddell & Reed Science & Technology fund. "They responded so rapidly and so effectively to the downturn that when it came to cutting production and inventory, there is not nearly the volatility in profit margins that you normally see," he says.