Under the rule of thumb that most people use these days, 20% down is a bear market. And if those are the terms you want to use, what's happened in the Nasdaq Stock Market is thoroughly ursine.

The

Nasdaq Composite Index

is more than 25% off the closing high it reached March 10, and better than half of Nasdaq stocks are more than 40% off their 52-week highs. Lately, if a stock symbol has four letters, it's been red. Day after day after day.

But for Wall Streeters who lived through the bear markets of 1981 to 1982 or worse, those of 1973 to 1974, the Nasdaq's fall over the past month -- 20% or not -- does not a bear market make. Particularly given that it had exploded up 87.7% from its October lows to its March high.

"Bull markets can retrace as much as a half of the prior gain and still be in a bull market," says Larry Rice, chief investment officer at

Josephthal

. "Considering where

the Nasdaq came from in the last three years, a 20% correction is just pennies."

Kodiak Arrest on the Nasdaq Composite

Source: Baseline

It's not just a matter of degree, but of the times. One of the things that made the experience in the early 1970s and early 1980s so debilitating was that the selling was so relentless for so long.

"

Those

were bear markets," says Hugh Johnson, veteran chief investment officer at

First Albany

. "It was a different experience than this is. You can't imagine what it's like when the thing goes on and on and on."

Ursa Major
S&P500 - 1971 to 1975

Source: Yahoo! Finance

An investor in November 1973 might have hoped that, with the

S&P 500

more than 20% off its highs, the worst was over. It was not. The market would continue to grind lower, day by day, week by week, until October of the following year. By the time it was over, the S&P would be halved.

"It was like watching paint dry," says Rice. "Every day the market just went down."

One could argue that the current environment simply doesn't allow for that kind of market. Just as the run-up in techs came so quickly and violently, so will any downturn.

"Investors are very impatient," says

DLJ Investment Management

chief investment officer Stanley Nabi, a (gasp) value investor. "The correction will complete itself very rapidly. It will last a few weeks and it will be over and then we'll be off to the races again."

Though the race may not be so hotly run.

"At that point, a lot of people will have gotten a little more religion," says Nabi, "and they'll be a little more sane in their investing."

For the selling to give way to one of those wrenching bear markets of yore, it would need to get much more severe than anyone is talking about just now. "The only way I could see it is if we had a major break -- 40% to 50% -- in the Nasdaq stocks that carried into the rest of the market," says Richard Dickson, technical analyst at

Scott & Stringfellow

in Richmond, Va. "That would require an awful lot of carnage in the technology area."

That type of drop seems unlikely, but the pain that technology investors are feeling is real. When your portfolio is hemorrhaging, the market's moniker ceases to matter.

"I don't think this is a bear market, but it doesn't matter what you call it," says Johnson. "It's painful if you're overexposed to tech stocks. Which I am."