Every now and again, investors can look at mutual fund performance charts and think they see an undiscovered gem, some issue that no one has heard about that appears to have a reasonable strategy, below-average expenses, and a place at the top of the charts.

More often than not, however, short-term performance leaders are no diamond in the rough - they're cubic zirconium or fool's gold.

That certainly appears to be the case with the Foresight Value Fund, the top mid-cap growth fund through the first half of the year, according to Morningstar Inc. It may be the poster child for why short-term performance should not be greeted with blind enthusiasm.

Typically, a fund with fabulous-but-volatile short-term performance will regress quickly to the mean, so that someone buying into the hot streak actually catches a coming cold spell.

Foresight Value is up more than 45 percent so far in 2009, or about four times the gain of its average midcap-growth category peer and nearly eight times better than the average stock fund, according to investment researcher Morningstar.

Foresight Value was started in 2004 by Michael Bissell, a chartered financial analyst who has a day job in engineering and runs the fund on the side. Bissell has yet to get a ticker symbol for the fund, noting that he hoped to have a decent five-year record before taking the steps - and paying the price - for getting a ticker.

Although many small funds do not go through the process of getting a ticker, investors should approach them with caution, because it may mean that the fund does not meet certain listing criteria or does not follow all back-room procedures required for having a ticker.

With Foresight Value, Bissell not only runs the money but he also serves as transfer agent, accountant, and administrator - roles typically handled by independent third-party firms, adding an extra layer of professionalism, protection, and cost. Instead of sending your deposits to a third-party administrator, you send them directly to Foresight's office in Katy, Texas.

Bissell himself will handle those deposits, just as he returns calls to the firm's customer-service lines.

That is not something your typical fund manager does. In fact, it is reminiscent of the 1970s and 1980s, when the number of new funds exploded and small money managers would sprout a new fund from their dining table and run it there until they either gave up or attracted attention and money.

He is also the fund's biggest investor, with his cash representing about 90 percent of the fund's assets.

"I could just invest my family's money on my own, without the fund, but I'm trying to establish a record," Bissell said. "If you do it on your own, nobody is going to know anything about it. If I can establish a record, the next step - getting the ticker and hiring an administrator and becoming a much bigger fund - becomes much easier."

Data-tracking firms such as Morningstar and Lipper Inc. may have basic performance information on funds without a ticker, but they are not likely to be doing significant analysis or research.

Foresight Value's documents - which you can see at www.foresightfunds.com - show a fund that buys and holds undervalued stocks until they reach the manager's estimate of their intrinsic business value. As an extra measure of safety, management purchases only companies that are debt-free, or that have sufficient resources to easily repay debt.

With 15 to 30 stocks in the portfolio, Foresight Value has concentrated holdings. The top 10 holdings, as of March 31, amounted to two-thirds of the nearly $400,000 left in the fund.

I say "left" because Foresight Value's hot streak is actually a bounce-back from a particularly miserable 2008. Where the average stock fund lost about 40 percent last year, Foresight Value dropped about 60 percent. The top holdings list shows several big-name, volatile stocks, including financials, energy, and basic-materials issues that have lived through a wild ride over the last 18 months.

That is why the current run should not exactly inspire confidence. Foresight Value's annualized losses since opening in 2004 are about three times bigger than the shortfall registered by the Standard & Poor's 500 stock index.

In the end, Foresight Value is likely to prove the adage that any fund can top the charts once, but that staying on top for the long haul is a much tougher task.

Chuck Jaffe is senior columnist for MarketWatch. You can reach him at cjaffe@marketwatch.com or Box 70, Cohasset, Mass. 02025-0070.