Few things reflect investment fads and the get-rich-quick mentality better than the commercial real estate market.

There is something about this market that seems ripe for exploitation. And, since so many investors spy the opportunities simultaneously, they tend to knock each other off. Boom becomes bust.Some of the biggest institutions in America have played the game and lost.

Within the past 15 years, for instance, large commercial banks tried to manage commercial properties and found the task required a lot more talent than the mere understanding of an income statement.

Much of the multibillion-dollar financial debacle of the nation's savings and loan associations can be traced to a lust for real estate profits and a departure from common sense. They guessed wrong on their real estate ventures.

Real estate partnerships sold millions of people on the idea of cashing in on the big tax deductions of real estate. What a game; the enterprise didn't even have to make a pretax profit. Tax deductions would be the profit.

Then Congress removed the tax deductions, suddenly causing the real estate market to be one of many sellers and few buyers, a situation that brings prices back to reality with a thud.

Builders, themselves, are among the worst players of the game. So true is this that it has become almost axiomatic that a sound way to make money in real estate is to wait until the builder gets into trouble and then lowball him.

Decade after decade a very few investors with great foresight ride the real estate cycle to the top and get off, leaving the vast majority of investors to ride it back down. Hot markets cool quickly; big losses replace big hopes.

So much overbuilding has occurred during the past few years that rents in some areas have actually fallen. In those areas, says George Puskar, chairman of Equitable Real Estate Investment Management, "real estate has actually been subsidizing corporate America."

Puskar observes that rents are the second biggest expense for companies - after payroll and benefits - and rents have been flat or falling because of the oversupply.

Strangely, while commercial real estate attracts innovative, daring and often highly successful entrepreneurs, as well as the biggest institutional investors, it often has been run by the seat of the pants.

In the past, losses meant nothing to some of these entrepreneurs, developers and promoters because they believed tax deductions, inflation and divine intervention would bail them out.

The tax deductions were eliminated, inflation calmed down in the 1980s and the divine interveners apparently became occupied elsewhere. Only then did some investors learn that real estate is a business.

It isn't, after all, like stocks and bonds, which have liquid markets. Hot real estate markets seem to be made up of all buyers, but in a flash they become markets of all sellers. The Sun Belt experience illustrates.

Puskar states the newer, businesslike approach:

"You want to position investments in properties that will have strong, steady cash flows over time and not be subject to boom-bust cycles. You can't be successful looking to buy in on a surge and sell quickly before a drop . . . "

Still, if the past remains a criterion, something new will be introduced into markets in 1989 that will resurrect the same old bullish enthusiams that lead to disaster.

What will it be? Hard to say. However, there is growing concern among important corporations owning first-class real estate that they keep on the books at only a fraction of its market value.

That's a dangerous practice these days because it might invite raiders. The raiders might not want the company and its products nearly so much as that undervalued real estate.