With the market in rally mode, a lot of fund investors will venture to open their statements or measure performance when they get their midyear paperwork.

While the numbers will be improved - the average stock fund is up more than 6 percent year to date - the emotions they raise will go to two extremes. Fund investors will either feel better about their portfolio because of its bounce-back or will feel even more frustrated about their investments because their duck-and-recover financial strategy is not working fast enough.

It is an odd time and place for investors brought up on the idea that funds will help them reach their long-term financial goals. Their funds are up enough that investors historically would have been happy with this kind of result spread out over an entire year; the average growth fund, regardless of cap size, has gained more than 10 percent thus far in 2009. And yet, because the average stock fund lost 40 percent in 2008, the current rebound feels skimpy; it is not enough to put the retirement plan back on track.

Outside of pulling money out of the market, portfolio moves in 2008 were like rearranging the deck chairs on the Titanic; you might have thought the view was better, but you were still taking on water. Now, investors face a similar conundrum, worried that they might swap themselves right out of a rebound or blow up a long-term plan based on short-term gut feelings.

"One is much better served looking for opportunity than trying to mute risk," said Michael Stolper, who runs the advisory firm Stolper & Co. in Southern California. "If you hate your fund, you likely misjudged market risk and/or the manager's style. If you still love him, you successfully aligned your expectations with the product. If you're not sure, take a nap."

That resting period would last long enough until the fund makes it clear that it meets or misses your needs.

Experts often advise patience and warn against letting short-term results dictate anything, but they do not deny that this time may be different. After the abysmal record most funds put up in 2008, an investor should be looking at the young recovery of 2009 to make sure that the fund's relative performance was expected. If the fund had a bigger-than-average loss last year, and its '09 gains are undersized compared with peers, that is a problem; investors are getting the worst of both ends.

If, however, it was able to offer some measure of downside protection - losing significantly less than its peer group in '08 - but it has not cashed in completely on the recovery, that might be acceptable for a risk-averse investor.

"So, should an investor be happy with a fund that is up materially for the year? Maybe," said Gregg Brewer, executive director of research at Value Line Inc. "The better question to ask would be, 'Is this fund doing what I bought it to do?'

"By using a mutual fund, you are outsourcing an aspect of your portfolio. You want to make sure that the person or people you are outsourcing to are earning their keep. That may not mean being the top fund, it may mean being a middle-of-the-road performer that has less volatility. So, to gauge satisfaction, people should go back to their reason for owning it. If it is still performing up to that expectation, you should be happy with the fund's performance."

And while the year-to-date and 2008 time horizons are most fresh and painful in the minds of investors, they are simply the most recent, but not necessarily the most important.

"I always find it baffling when rates of return are given as facts when time horizons are arbitrary," said Brian Grodman of Grodman Financial Group, of Manchester, N.H. "If the investor views only the past 18 months, then the statistics will be different from an analysis that includes 2007 or the years preceding."

The bigger questions, Grodman maintains, are: "What is the investor's time horizon; when do they need the money? When did the investor purchase the fund, and how has it performed, on the whole, from that date? Have the fundamentals changed?"

Ultimately, the market's rally creates its own pressure on investors. During the decline, investors were making the decision of whether to ride things out or get out; today, they are trying to make sure they get their share of the good times.

"The investor's biggest obstacle right now is his own behavior, because we're moving from a time when they were fearful to one where they want to be greedy," said Frank Armstrong of Investor Solutions, of Miami Beach, Fla. "The temptation to measure performance from the high-water mark - and the low - is overwhelming, but it's not necessarily wise. It's not just 'How has the fund done since my portfolio peaked or bottomed?' it's 'Am I satisfied, in general, with the fund over time, and do I think I will remain satisfied in the future?' "

Chuck Jaffe is senior columnist for MarketWatch. He can be reached at cjaffe@marketwatch.com or at Box 70, Cohasset, Mass. 02025-0070.