We've been through one of the most volatile market periods in modern times. If you're like me, you felt every inch of it, from the sickening plunge driven by the financial crisis to the 50% moon shot brought on when investors realized the world was not going to end after all.

And yet, the worst part for me was news that many individual investors missed the massive rally. Scared out of the market when blood was running in the streets, many are only now thinking of getting back in.

According The Washington Post, the Dow's drive back over the 10,000 mark was fueled largely by institutional investors. By contrast, individual investors pulled $205 billion out of mutual funds during the crisis, but only $56 billion returned before the Dow hit 10,000.

I must admit this news hits me hard, because I've always advocated that investors stay in the market through good times and bad. Like Warren Buffett, I believe market timing is impossible on a consistent basis, and investors who are constantly jumping in and out of the market wind up at a huge disadvantage.

I heard this a lot during the crisis after the market had plunged: Why don't I just sell all my stocks until things get better? As we're now seeing, again, things just don't work that way. The market gives so many head fakes that it's impossible to know when is the right time to "jump back in." Instead, investors who try the timing game wind up missing gains like these:


Post-March 9 Gain

Las Vegas Sands (NYSE:LVS)


Dendreon (NASDAQ:DNDN)


Hecla Mining (NYSE:HL)


Interoil Corp. (NYSE:IOC)


Conseco (NYSE:CNO)


Advanced Micro Devices (NYSE:AMD)


Golden Star Resources (AMEX:GSS)


Data from Capital IQ through Jan. 4, 2010.

And here's another lesson we're all re-learning: The market does not follow or walk in lockstep with the economy. Oh sure, various bits of news -- good or bad -- can whip it in one direction or another. But overall the market is a leading indicator. The 50% rally took place despite rising unemployment and continuing massive layoffs, record numbers of mortgage defaults, and glum news from businesses everywhere.

But that didn't matter to Mr. Market. Buffett, reinforcing once again the futility of market timing, said in his most recent annual letter to Berkshire Hathaway shareholders: "We're certain, for example, that the economy will be in shambles throughout 2009 -- and, for that matter, probably well beyond -- but that conclusion does not tell us whether the stock market will rise or fall."

Think about that the next time you hear the doom-and-gloomers talk about continuing high unemployment and a faltering economy. The world's best investor says none of this helps us predict where the market's headed.

Buying good companies at fair prices and staying invested through thick and thin is the only way to secure the massive 10-baggers in your portfolio. This was the top lesson David Gardner had to offer after Marvel Entertainment became his first 14-bagger in the Motley Fool Stock Advisor service. After seven years in which the S&P 500 was nearly flat, Marvel returned 1,300% before being bought out by Disney.

If you take only one lesson from this article, let it be this: The only way to achieve those life-changing gains is to hold your ground and not be scared out of great companies -- and to stick with them for many years.

For the next 30 days you can see every one of David's current recommendations for free, including his top five stocks for new money right now. Here's more information.

Fool analyst Rex Moore once led a horse to water and made him drink. Berkshire Hathaway is a Motley Fool Inside Value selection. Berkshire Hathaway and Marvel Entertainment are Motley Fool Stock Advisor recommendations. Disney is a recommendation of both Inside Value and Stock Advisor. The Fool has a financial position in Berkshire Hathaway, and a disclosure policy that needs no timing.