For more than two years, we have told ourselves that the crash of 1987 was an accident, signifying nothing. The major stock indexes recovered fully. The historic peak on the Dow Jones industrial average is 2810, registered this year on Jan. 2.

Without being too dour, I can't help but mention that that same opinion was also widely held in 1930. To quote from the New York Times of April 2, 1930:

''Despite the sharp rise in prices during the last two weeks, investment trust executives are optimistic concerning the outlook for the stock market during the next few months. Aside from technical reactions, which might arise from temporary overbought situations, they can see nothing but a continued advance.''

The conventional wisdom was wrong 60 years ago. And the brokerage house Kanon Bloch Carre thinks it's wrong today. In fact, in the opinion of KBC's director of research, Tyler Jenks, the great bull market that started after World War II has come to a close.

Jenks bases his opinion on a theory he calls the ''hyperwave.'' From time to time, he says, various markets pass through a boom-bust pattern, tracing four steps up and three steps down.

First, there's a period of indecision, when the market never exceeds a certain price. That neatly describes the period from 1966 to 1982, when, five times, stocks tried -- and failed -- to hold above 1000 on the Dow.

Next come three periods of rising prices, with each stage accelerating faster than the one before. In the fourth phase, the ''blow off,'' the market rises almost vertically. And so it was, from December of 1986 through the following, glorious spring and summer of '87. Prices leaped 43 percent in just seven months.

Then comes phase five. Prices collapse. Typically, says Jenks, all the gains of the phase-four blowoff are lost in a matter of days. The game is over.

But markets don't go gently into that good night. Phase six brings a strong bounce upward. In fact, it recovered its entire loss -- helped along, Jenks thinks, by the strength of the giant Tokyo market.

But at the end of January, he says, the market slipped into the hyperwave's final stage. It's not a pretty one. Prices move relentlessly downward, sometimes gradually, sometimes sharply, interrupted by just enough upward moves for investors to think, mistakenly, that the worst is over. ''In the 1930s, people were encouraged to buy the market all the way down,'' says KBC's senior analyst, Walter Stone.

The seventh phase generally lasts for two or three years, and brings the market back to its starting point. That would be around 1000 on the Dow.

Buttressing his bearish view of American stocks is the fact that trading volume (demand for stocks) has been in general decline ever since the '87 crash -- and long-term trends in volume precede long-term trends in price.

Several international markets are also finishing their hyper- waves, Jenks says, among them Japan, Canada, the United Kingdom, Australia, Hong Kong, South Korea, Sweden and Switzerland. Germany, France, Italy and Taiwan don't fit the pattern, but he doubts they can rise with so many other markets in decline.

In short, says Jenks, this is no time to buy stocks or even to hold them. He advises that you own money-market mutual funds or funds that own government bonds, top-quality corporate bonds or top-quality municipal bonds.

''If I'm right,'' he says, ''I protect my money while others are losing it and make total returns of 8 to 10 percent. If I'm wrong, I still have those returns and I'm out only what I would have made from stocks.''