As investors may have learned in the past few unsettling years, it pays to be flexible. The recent upheaval in the stock market has demonstrated the benefits of a flexible and wide-ranging investment approach.

Unfortunately, many mutual funds are locked into being pretty much fully invested in a certain segment of the market, no matter how attractive or unattractive that corner of the market may be. But some funds have a wider mandate and the freedom to invest where they want, when they want. These go-anywhere funds may have an edge in the current uncertain market environment. If you like to give your money manager a lot of free rein to exercise his or her skills, you may want to consider one of the following excellent options.

FPA Crescent (FPACX)
This balanced fund invests in a mix of bonds, cash, and stocks of all sizes. Longtime manager Steve Romick has skippered the fund for more than 17 years, employing a flexible, valuation-conscious approach. Romick doesn't stick to a predetermined asset allocation but adjusts the ratio of investments based on where he sees opportunities. Right now, Romick is taking a very cautious stance on the U.S. economy and has stuffed approximately 44% of the portfolio in cash, with only about one-third of assets in stocks. Corporate bonds make up the majority of fixed income holdings in the fund right now.

While Romick isn't exactly loving stocks these days, he is finding value in the energy sector, which accounts for 22% of the fund's equity allocation. Names such as domestic oil companies Apache (NYSE: APA) and Occidental Petroleum (NYSE: OXY), as well as the U.K.'s Ensco (NYSE: ESV), are among the fund's many energy holdings. Romck believes that these companies offer compelling valuations and, when combined with higher expected oil prices, should outperform the market.

The fund has posted an impressive 10.4% annualized return over the most recent decade and a half, ahead of 99% of its peers in its Morningstar peer group. If you're looking for a fund that takes a measured approach to investing, FPA Crescent is a good choice.

Muhlenkamp (MUHLX)
Manager Ron Muhlenkamp has had a few challenging years, but the fund hasn't lost its long-term magic. This concentrated fund has landed pretty squarely in the large-blend or large-value corner of the Morningstar style box over most of its life, but don't let that fool you into thinking this fund is a one-trick pony. Muhlenkamp has the flexibility to move into bonds or cash if market conditions dictate, although stocks have been the primary focus here for most of its life. Cash currently accounts for 10% of portfolio assets, as management is cautious on the current state of the economic recovery.

Sector concentrations are also the norm here. The fund was heavy in industrial materials and energy stocks a few years ago but has lightened up in those areas and now boasts a heavy allocation to health-care companies. Muhlenkamp believes that increased demand for health-care services will be a boost to the sector, despite increasing pricing pressures. The fund has meaningful positions in UnitedHealth Group (NYSE: UNH) and Pfizer (NYSE: PFE), both of which have returns on equity in the range of 15%-20% and are trading at reasonable valuations, lining up with the fund's focus of owning good companies at cheap prices. This fund can be volatile in the short run, but in the long run, it has done a first-rate job at navigating the market's ups and downs and making money for its clients.

Osterweis (OSTFX)
Osterweis is another fund that doesn't like to confine itself to just one corner of the market. The fund can buy investments of many shapes and sizes, including small- and large-cap names, as well as corporate bonds. Mid-sized stocks account for roughly 45% of the fund's equity exposure right now. Management has cut back its defensive position somewhat, moving from a roughly 50% cash and short-term bond allocation back in late 2008 to about 18% now.

Like Muhlenkamp, health-care names play a big part in the portfolio, to the tune of 24% of equity assets. The team likes this sector, including top holdings Johnson & Johnson (NYSE: JNJ) and Medtronic (NYSE: MDT), because drivers of revenue and cash flow at these companies are less dependent on the broader economy. In addition, management likes that these names are strong dividend payers and have the ability to increase dividend payments in the future. Osterweis has racked up an 11.1% annualized gain over the past decade and a half, beating the S&P 500 in most calendar years. This fund is a fine choice for investors who prefer a dose of small- and mid-cap exposure in their go-anywhere investment option.

The market is likely to remain volatile throughout the rest of the year as the economy struggles to stand on its own in the absence of government support. Time will tell whether the current soft patch we're in will resolve favorably or drag the economy back down into recession. Amid such uncertainty, the flexibility of go-anywhere funds like these may be just the ticket to riding out the economic storm.

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Amanda Kish is the Fool's resident fund advisor for the Rule Your Retirement investment newsletter. At the time of publication, she did not own any of the funds or companies mentioned herein. UnitedHealth Group is a Motley Fool Inside Value and Motley Fool Stock Advisor recommendation. Pfizer is a Motley Fool Inside Value recommendation. Motley Fool Options has recommended buying calls on Johnson & Johnson, which is a Motley Fool Income Investor selection. The Fool owns shares of UnitedHealth Group and Medtronic and has a disclosure policy.