Imagine that a year ago, for example consider Oct. 8, 2007, you had $10,000 to invest. You wanted something safe, so you put it into a fund that matches the Dow Jones Industrial Average, which closed that day at 14,043.

A year later, after the market closed at 9,447 on Oct. 7, your investment was worth only about $6,700.

Of course, that's the opposite of how an investor wants to operate. The trick is to follow the old saying: Buy low, sell high. Right now, the market is low.

If you put in $10,000 now, and the market exactly reverses itself over the next year, that $10,000 would become $14,900.

We can't know the stock market will do that, but the historical trend is for the Dow Jones to rise. From October 2003 to October 2007, it went from about 9,700 to above 14,000.

Researchers find that index stocks -- those that match either the Dow Jones or the Standard and Poor's 500 -- outperform funds that try to pick the best stocks to buy.

While you can never know for sure if we're at the low part of the dip, some advisers see an opportunity to pick up solid investments.

James B. Stewart says in the Wall Street Journal that he is buying during the financial crisis because that is when stocks are cheap. He also points out that his strategy involves plans to leave money in place for longer than five years.

(And, if you had invested five years ago when the market was at 9,674 and taken it out four years later at 13,522, you would have made nearly $4,000 just by waiting patiently.)

The Motley Fool also said this week that now is the time to buy stocks, especially boring ones from reliable, large companies that make products people will have trouble cutting back on during a recession.

Nobody can ever tell for sure when things have bottomed out. Once that's known for sure, you have missed part of the turnaround. But it's clear that some experts see the scary times over the last few weeks as a great opportunity to get in position for the future.