Investor Insight head John Mauldin says "buy and hold" investing was "basically foisted on investors by an industry that wanted to keep assets under management."

"So, if you're a long-only manager and that's your hammer, then all the world looks like a nail" Mauldin tells The Financial Times.

"If you're a fund manager, you're not going to stand up and say: 'You know, I don't think it's a good time to invest in my fund. I think we'll just shut it down.' You'd be fired!"

In fact, investors should disabuse themselves that buying equities at all is investing, Mauldin says.

“It’s a different form of gambling. And you’re gambling on rising productivity, you’re gambling on rising price-to-earnings ratios, you’re gambling on all sorts of things.”

Mauldin says there will be some excellent commercial real estate investing opportunities in the U.S. and probably in the U.K. and parts of Europe, in a few years “as the commercial real estate debacle just craters.”

“You’re going to be able to pick up very, very good properties that cash-flow from day one,” he prophesies.

Buy-and-hold stock investing works fine if you have a long enough time horizon, says David Blain, chief investment officer of D.L. Blain & Co.

But in a secular bear market — which many forecasters believe is what we've got now — a buy-and-hold approach can be disastrous.

"Letting someone's portfolio decline 50 percent isn't prudent management," Blain notes.