Whether you order the new menu item would depend on several factors, ranging from your taste for the specific dish to its cost and more. But if that favorite restaurant is a steak house and the new item is a delicate fish, you might be worried that ordering the special would be a waste of money.

The same phenomenon and thought process exists in mutual funds, and it was proved recently when two big-name fund firms rolled out new offerings that represent a departure from their usual line-up.

Wasatch Advisers announced the opening of its new Strategic Income fund, while Janus Capital Management unveiled Janus Advisor Long-Short, which will be managed like a hedge fund.

News of a new fund from either company tends to be greeted with excitement, as both firms have a history of starting funds that get off to a good start.

Moreover, investors love being in on the ground floor of a fund, especially because the so-called "new fund phenomenon" purportedly gives issues an extra pop.

But the newest issues — neither of which has a ticker symbol yet — are head-scratchers.

Wasatch has a terrific record on stocks, but zero reputation for running fixed-income portfolios; Janus is at its best when the market favors growth, but now is creating a fund that time the market and avoid growth stocks when they are out of favor.

In each case, while the new funds are driven by research, the addition smacks of marketing, an attempt to stem outflows by filling a new niche.

Janus and Wasatch are hardly alone; the Artisan Funds, for example, best known for running small- and mid-cap funds, recently announced a new large-cap offering. There are others, and there will be more.

In each case, the investor needs to approach the new fund a bit like a baby bear; it may look cute and cuddly, but it could have a vicious temper.

Says Thurman Smith of the Equity Fund Outlook newsletter: "With a new fund that invests in a way the firm hasn't really done it before, step back and let some numbers come in before touching them. Don't be tempted too quickly."

Indeed, compare the new funds to their existing peers and take a "best of breed" approach, making your pick from the top of the list of available funds.

It is hard to project a new fund into that group, just because management is adept at running funds with a different style. After all, if management was brilliant at running funds in its new style, it might have started doing it a long time ago.

"If they were opening a fund similar to what they do best, taking a chance makes sense," says Jeff Tjornehoj, research analyst for Lipper. "But exceptional skill in one area doesn't mean someone is exceptionally skilled in others. If a new fund makes you scratch your head and wonder 'Are they good at that too?' you shouldn't buy until that question is answered over time."

Chuck Jaffe is senior columnist at Marketwatch. He can be reached at jaffe@marketwatch.com or Box 70, Cohasset, MA 02025-0070.

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