When intelligent men give warnings like this, I always take heed:

WARNING: The following is not a recommendation to buy, sell or hold any financial instrument.

Fred Hickey is used to going against the crowd.

Everyone scoffed in 1999 when the veteran Nashua, N.H., stock market guru, who publishes the influential High-Tech Strategist investment newsletter, warned that the tech bubble was going to pop.

And they dismissed him as a wild alarmist early last year when he said house prices were going to slump.

What's his view now?

"I think we're going to have a crash, across the stock market," he said Friday.

Yes, Wall Street has been flirting with new highs. And the stock market cheerleaders on TV are waving their pom-poms madly, urging you to put more money into the market.

But people with long memories know that is exactly the time to get nervous.

Think: 1929, 1987 and 1999.

Hickey isn't alone in his worries. As reported here, several top investment managers - from Warren Buffett to Jeremy Grantham to Manu Daftary - have been pulling back from the stock market and hoarding cash.

Many simply think equity prices are too high.

Hickey's viewpoint is more alarming. He thinks the real estate slump is going to develop into a crisis that will spread across the economy.

Hickey points out that housing sales have collapsed, prices are eroding, and a whole army of homeowners on adjustable-rate mortgages face sharp spikes in their monthly payments as their introductory periods expire.

And he thinks it's going to get a lot worse.

"Even with everything we've witnessed to date, people still think it isn't going to be that bad, that it's going to be a nice, slow, measured (decline)," he said with disbelief.

Early last year Hickey backed his prediction by betting his own money against shares in high-end homebuilding company Toll Brothers.

He cleaned up. They've collapsed from $57 to just $27.81 as the housing bubble - to the astonishment of Realtors, naturally - finally popped.

He's closed that bet, but opened up two others: Against homebuilders WCI Communities and Lennar. Both, he notes, have big exposure to the wild Florida real estate market. WCI, he adds, is also running low on cash.

But it doesn't stop there, he argues. If housing crashes, the debt-ridden U.S. consumer will stop shopping. And the knock-on effects will follow through across the economy - and around the world.

Is he right? We'll see, one way or another.

But he's certainly putting his money where his mouth is. Hickey is betting against a wide range of U.S. stocks, including Google, IBM, Motorola, Intel, Apple, Research In Motion, Texas Instruments and Amazon. "I've got the biggest number of short positions I've ever had," he says.