Roughly a year ago -- as you may painfully recall -- emerging markets hit the skids and our domestic market took a tumble, too. The story isn't exactly the same in 2007, it's true. Indeed, the way U.S. investors shrugged off the Chinese market's recent pullback was downright impressive.

Still, as we head into summer -- when lighter trading volume can increase the possibility of heightened volatility -- it's worth asking: Is this the calm before the storm?

That's particularly true when you factor our lengthy bull run -- which has lasted nearly five years now -- into the mix.

Don't get me wrong
I'm certainly no advocate of market timing. That's a loser's game, and even during dramatic and protracted upswings, Mr. Market can still serve up bargains. ExxonMobil (NYSE:XOM), General Electric (NYSE:GE), and Qualcomm (NASDAQ:QCOM), for example, all sport price-to-earnings ratios (P/Es) below their five-year highs. Verizon (NYSE:VZ) and Oracle (NASDAQ:ORCL) fit that profile, too, while Merrill Lynch (NYSE:MER) currently trades with a P/E that hovers around single-digit territory despite a track record of whipping up on the market.

That said, I think now is a fine time for savvy types to take stock of their portfolios and consider adding ballast in the form of Grade-A mutual funds. Funds can help take the sting out of pesky performance gyrations, adding carefully calibrated diversification to a portfolio that might, for instance, be heavily tilted toward the market's little fish or value-oriented stocks -- two asset classes that have fared especially well during the latest bull run.

Go growth
With that as a backdrop, I think now is a fine time to invest against the grain by tilting toward growth. True, owing to heightened earnings-growth expectations, that asset class can be subject to the slings and arrows of irrational exuberance. Funds, however, can provide an investment vehicle that strikes a winning risk/reward profile -- provided you choose 'em Foolishly.

At Motley Fool Champion Funds, the investing service I head up, I look for, among other things, low expense ratios; smart, emotion-free investment strategies; and managers who stick to those strategies through upswings and downturns. Indeed, for the kinds of managers who make our grade, sell-offs practically scream "buying opportunity."

So far, that criteria has worked out well: All of our recommendations are in the black, and taken collectively, they've bested their benchmarks by a double-digit margin.

The Foolish bottom line
Now may be a perfect time to be contrary and put growth stocks to work. When it comes to choosing the right funds, the best places to start are low expenses, sound strategies, and battle-tested managers.

Of course, if you'd like to sneak a peek at our winner's list -- which includes a clutch of growth-oriented keepers -- you can click here to give Champion Funds a risk-free spin. Whether we experience a sell-off this summer or not, funds can provide a way to participate in bull runs and stay in the game when the bears roam. Can you say the same of your stock portfolio?

Take Champion Funds for a spin now and the Fool's latest premium report -- "The NEW Rule Makers: 5 Power Stocks You'll Never Want to Sell" -- is yours free. You'll also have access to our latest special reports: "The Challenge: ETFs vs. Mutual Funds" and "Add Kick to Your 401(k)!" Just click here for more information. 

This article was originally published on June 5, 2007. It has been updated.   

At the time of publication, Shannon Zimmerman didn't own any of the securities mentioned above. You can check out the Fool's strict disclosure policy by clicking right here.