A recent Wall Street Journal article highlighted the struggles that many Fidelity funds are enduring in this year's market. According to the article, only 39% of Fidelity's equity funds are in the top half of their peer group so far this year, compared to 64% during the same time period last year. Apparently, this is Fidelity's weakest relative showing of performance in the first five months of any year since 2000.

So what?

No, really -- so what?
Short-term performance is a terrible measure of overall fund quality. Even the best funds and fund managers will endure periods of underperformance, but their long-term performance speaks for itself. Short-term performance may be useful in telling us what's going on in the current market environment, but investors should never base their buy and sell decisions on it.

Unfortunately, investors aren't usually patient. In fact, investors typically trade in and out of funds so often that Morningstar now reports two sets of returns -- total returns and investor returns, which take into account when people bought and sold.

Taking a short-term view of investing is one of the quickest ways to drag your portfolio into the red. Listening to the media will only make it worse.

Behind the numbers
It's easy to be alarmed about Fidelity funds after reading the aforementioned article, but let's add some context. At least through mid-May, growth stocks were underperforming value stocks, meaning that funds concentrated in growth stocks have been more severely beaten down by the market. Since most Fidelity funds lean toward the growth corner of the style box, it's not a surprise that many of its funds are lagging this year.

Fidelity Magellan (FMAGX), for example, is a behemoth of a fund that invests in large-cap growth stocks like Google (NASDAQ:GOOG), Cisco Systems (NASDAQ:CSCO), and Apple (NASDAQ:AAPL). It's down nearly 12% year to date -- but its 10-year returns are beating the market, and it has a proven manager in Harry Lange.

Fidelity Balanced (FBALX) is a hybrid fund that invests in a mix of bonds and stocks, including Citigroup (NYSE:C), AT&T (NYSE:T), and American International Group (NYSE:AIG). It's down more than 6% year to date -- but it's ranked fourth in its category for 10-year returns.

Any fund can look terrible over a five- or six-month period, yet still be the best place for your money in the long term. Another five months from now, you could very well see a similar article praising Fidelity for climbing back to the top of the performance charts. The short-term news cycle, in other words, focuses on short-term performance -- and thus does investors a disservice.

Individual attention
So while short-term performance can make for good news stories, chasing it is one of the quickest and easiest ways to lose money in the market. Make sure you judge and evaluate your investments over the long run, no matter what today's hot news story tells you to do.

That's what we do at the Motley Fool Champion Funds investment service -- and our picks are beating the market by 20 percentage points. You can view all of our recommendations by taking a free 30-day trial, with no obligation to subscribe. Click here to get started.

Amanda Kish heads up the Fool's Champion Funds newsletter service. At the time of publication, she did not own any of the companies or funds mentioned herein. Google is a Motley Fool Rule Breakers recommendation. Apple is a Stock Advisor selection. The Fool's disclosure policy always keeps an eye on the horizon.