NEW YORK (CNN/Money) - October 9 is not a holiday, but come Thursday there's some reason for investors to celebrate.

That's because it will be the one-year anniversary from the day when stocks hit bottom in the bear market. Since then, the major stock indexes have been dancing with bulls.

Of course you may or may not have benefited, depending on how you handled your investment choices both before and after Oct. 9 last year.

Before you even account for dividend reinvestment, the S&P 500 has risen nearly 34 percent from Oct. 9, 2002 through the close of trading on Tuesday, and the Nasdaq has soared a whopping 71 percent. (For a closer look at the Nasdaq's ride and its prospects for more upside, click here.)

Meanwhile, the EAFE index, a common benchmark for diversified international-stock funds, rose more than 35 percent.

And despite a rough summer for bonds, the Lehman Brothers Aggregate Bond Index rose 4.4 percent.

Meanwhile, stable value funds, the most popular fixed income choice among 401(k) investors, held their own, delivering returns of about 5 percent through the end of August this year, the most recent period for which data is available, according to Hueler Analytics.

Most individual investors get their exposure to stocks primarily through their retirement savings accounts such as 401(k)s. And as a group, 401(k) investors have about 62 percent of their money in equities and the rest in fixed income.

So it's unlikely that you kept up with the stock indexes.

Nevertheless, you should have seen substantial gains in your account over the past year...if you were adequately exposed to stocks at the right time.

Certified financial planner Rick Applegate, who advises several 401(k) plans in his capacity as president of First Commonwealth Financial Advisors, says there are plenty of participants who were either overexposed to stocks or, lately, fixed income.

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And if they moved money into stocks throughout the year, they missed out on the biggest gains because they bought into a rising market.

That squares with findings from Hewitt, which tracks 401(k) participant behavior in large-company plans. Even though only 1 in 6 participants made any transfers in their 401(k)s last year, those who did tended to chase performance.

What's more, "people missed the fat pitch" on bonds, Applegate said. That is, they didn't heed the warning that interest rates would soon rise, pushing down the price of bonds, and take that as an opportunity to rebalance their bond holdings -- which had swelled thanks to a recent bull market in that arena.

When it comes to stocks, Applegate said, a lot of participants are still overexposed to one type of capitalization and investment style (often large-cap growth); they shun international investing; and they don't pay attention to whether their 401(k) choices are well-run funds and whether they perform in lock-step because there's a lot of overlap in their holdings.

The goal, Applegate said, is to have funds that have different investment styles and that perform differently from each other. And if you opt for actively managed funds, you want to have managers with a track record of running their funds well through both bull and bear market cycles and beating their benchmarks along the way.

Despite the well publicized travails of Enron employees and other workers who invested a lot in the stock of their employers who went bust, many participants in 401(k)s still are overexposed to company stock.

According to Hewitt, 401(k) participants in large-company plans (which typically are the ones offering company stock as an investment) had about 24 percent of their assets in company stock and had earmarked 20 percent of their regular contributions to buy more.

Even post-Enron, when some companies lifted their restrictions on when employees could sell their company stock holdings in a 401(k), "We didn't observe a huge change (in investor behavior) with respect to company stock," said Lori Lucas, Hewitt's manager of participant research.

Another study, done by the Employee Benefit Research Institute, found that in 2002, among those 401(k) participants who had company stock as an investment option, 14 percent had more than 80 percent of their assets invested in their employer.

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When it comes to owning company stock in your 401(k), "by and large, it should be limited," Applegate said. "Consider it to be high risk."

Indeed, he doesn't like to see more than 5-to-10 percent of a portfolio in all of one's high-risk investments combined.

Company stock is high risk, he explained, both because it's a single issue and you should never invest large amounts of your retirement money in just one stock, and also because it doubles your vulnerability to your employer. That is, if things go badly for the company, the stock price may suffer and you may lose your job.