NEW YORK (CNN/Money) - When shares of eBay broke the $100 level Tuesday, it was hard not to reminisce about the late 1990s. In fact, tech stocks across the board have been surging.

Even so, the vast majority are still well below their prices when the Nasdaq hit its now infamous 5,048 zenith on March 10, 2000.

But there are actually a handful of techs, including eBay (EBAY: Research, Estimates), that are higher. In fact, not only are they up, they're doing quite well: The 40 tech stocks in the S&P 500, S&P SmallCap 600 and S&P MidCap 400 indexes that fit this category are up an average of 65 percent since March 10, 2000. For a look at all 40 stocks, click here.

How have these bear-proof techs done it and can they continue to head higher?

Most of the stocks on this list deserve to be trading higher. The companies have, on average, posted 12 percent revenue gains over the past three years and earnings increases of 26 percent.

By way of comparison, companies in the S&P Information Technology Index have posted an average 12 percent sales decline and a 44 percent earnings drop annually over the past three years.

So fundamentals matter.

Looking at the 40 stocks in more detail, there are some definite trends. Video game stocks have all done well as companies like Electronic Arts, Activision, THQ and Take-Two Interactive benefited from the launch of Sony's PlayStation 2 in 2000 as well as Nintendo's GameCube and Microsoft's Xbox in 2001.

Despite the bear market, companies involved in transactions processing, not exactly a glamorous business, have continued to see strong demand. Companies that have benefited include First Data, Concord EFS (which First Data is acquiring), DST Systems and Fiserv.

And some of the biggest standouts are relatively unknown stocks that have prospered due to unforeseen events such as the war on terrorism and conflict in Iraq.

Shares of Flir Systems, which makes thermal imaging systems and infrared cameras used by the military and for homeland security, have surged a whopping 460 percent since the Nasdaq's peak.

CACI International, which lists the Department of Defense as a major customer for its networking and IT services, is up 137 percent. And disaster recovery services provider SunGard Data Systems, which helped retrieve data for customers that were housed in the World Trade Center, is up 45 percent.

With the exception of eBay, there really aren't any sexy tech stocks that were all the rage in the late 1990s on this list. It just goes to show that latching onto hot new trends may not be the best of ideas.

"A lot of tech stocks that were 'Steady Eddies' were not subject to hype. They were boring stocks," said Todd Campbell, president of Watchdog Research, an independent research firm. "But those stocks had strong top- and bottom-line growth."

Past performance is one thing. Can these stocks continue to surge now that the market is once again infatuated with Internet commerce companies, telecom-equipment firms and semiconductors?

The answer would appear to be yes. For one, the 40 are actually gaining momentum. These stocks are up, on average, 28 percent since this year's market low on March 11. The Nasdaq is up 22 percent in the same time frame.

And despite this run, most of the stocks are still reasonably valued. The 40 trade at an average of just 22 times calendar 2003 earnings estimates -- and that includes eBay's P/E of 71.

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To be sure, that's a premium to the S&P 500's multiple of 18 times earnings. But S&P 500 earnings are only expected to increase 8 percent this year while the average estimated earnings gain for these techs is 43 percent.

And the 40 trade at a substantial discount to the S&P Information Technology Index's P/E of 31, even though the index has a lower expected earnings growth rate of 15 percent this year.

So tech investors getting tempted by the likes of Wall Street darlings Amazon.com, Juniper Networks and Broadcom shouldn't ignore the stodgier names on this list.

They've held up in the worst of environments of tech and still trade at a discount to today's hot momentum plays.