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. So far, anyway, the Chinese market's dramatic downturn hasn't had a ripple effect: Indeed, the way U.S. investors have shrugged off the pullback has been 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 particular 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. Cisco (NASDAQ:CSCO), Procter & Gamble (NYSE:PG), and Intel (NASDAQ:INTC), for example, all sport price-to-earnings ratios (P/Es) below their five-year highs. Wal-Mart (NYSE:WMT) and Pfizer (NYSE:PFE) fit that profile, too, while ConocoPhillips (NYSE:COP) and Toll Brothers (NYSE:TOL) currently trade with P/Es that hover around or below single-digit territory despite 10-year track records 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 delivered a total average return of roughly 40%, besting their benchmarks by more than 14 percentage points.

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 Champion Funds winner's list -- which includes a clutch of growth-oriented keepers -- you can click here for a free 30-day guest pass. 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? Not to worry: A foundation of world-class, championship-caliber funds awaits.    

At the time of publication, Shannon Zimmerman didn't own any of the securities mentioned above. Intel, Wal-Mart, and Pfizer are Motley Fool Inside Value picks. You can check out the Fool's strict disclosure policy by clicking right here.