If the current markets have convinced you that you're not really a long-term investor -- and by that I mean five years or more -- and you want out, I have a word for you.

Wait. Don't sell at the bottom.

But how long?

If past financial crises are any guide, data from Morningstar shows that in recent fits of market panic, it pays to wait three to five years after the crisis. Because by then you'll be ahead.

The point is taken form Morningstar's look at stock and bond markets in the wake of the October 1987 stock market crash, the August 1989 savings and loan crisis, the September 1998 bailout of Long Term Capital Management, the March 2000 dot-com crash and the September 2001 terrorist attacks.

In three out of five panics, if you'd held on to an all-stock portfolio for five years, you would have been substantially better off than if you had sold at the low point.

Five years after the '87 crash, the stock portfolio would have a 98.6 total return; after the S&L crisis, 58 percent return; and after the terrorist attacks, a 40.1 percent return. Long Term Capital's five-year record was up only 5.1 percent and after the dot-com crash, you would have been down 14.8 percent.

Can't hold on for five? The three year-record is good, too, in three out of five and OK in the fourth. Even a year helps stocks get back to even and off the bottom in most cases.

Six months, though, won't do it. Three times out of five, stocks were still down.