When it comes to commodities, investors are getting mixed signals. On the one hand, the numbers don't look promising. Following a red-hot run, the sector has languished this year amid signs of slowing U.S. economic growth. Many analysts believe the slowdown could keep prices for various raw materials in check for months to come.

Even so, Wall Street has continued to introduce and tout an array of commodity-based products, including hedge funds, exchange- traded funds, derivatives contracts and other investment vehicles.

It seems like a contradiction. Why would commodity pros urge investors to plow money into a sector with seemingly dim prospects? But, for the most part, the experts aren't advising investors to make commodities the focus of their portfolio. Indeed, only a few contrarians think the sector is due for an upswing and urge investors to bet accordingly.

Instead, most pros are arguing that the sector is still a good bet -- in moderation. They're advising investors to pick up select commodities with good prospects or make bearish bets that will profit if the sector continues to drop. And they typically recommend a relatively small commodity allocation, perhaps 5 percent to 15 percent of an individual's portfolio, with the rest in stocks, bonds and more traditional investments. Either way, the experts say, a modest allocation in commodities can prove profitable for investors who stick around the sector and choose wisely.

A relatively small niche of commodity-focused pros -- the ones who were around before the recent boom attracted more attention and manpower from Wall Street -- have advocated such strategies for years, usually to little avail. This time they are hoping that enough investors have schooled themselves about everything from copper to soybeans during the boom that they will stick around for the long run.

"For a long time, the only people who really had access to -- or interest in -- these markets were a few multimillionaires in Greenwich," the Connecticut town that's home to many hedge funds, says Aaron Smith, managing director at Superfund Asset Management Inc., a $1.6 billion commodity-futures fund based in New York. "That's changing. Now, if people see an opportunity in the market, they want to go after it, regardless of how big they are."

The basic trading units in the commodities market are futures -- contracts that guarantee delivery of an underlying asset at a fixed price on a certain expiration date. Although most trading volume these days takes place in financial contracts tracking foreign currencies and the like, the oldest futures contracts track commodities like wheat and pork bellies.

Such contracts can be used to speculate on future market moves or to guard against unexpected market declines in the underlying commodities. But because futures bets are financed using relatively little cash up front, with the rest essentially borrowed as so-called leverage, it is possible for an investor to lose more money than he put up in the first place if the market moves against him.

On the bright side, federal regulations on futures trading make it easier to place bearish bets in those markets than in stocks. Futures traders say that setup makes it just as easy to profit during market downturns as upturns -- assuming the investor guesses the market's direction correctly.

Mr. Smith says his firm racked up big profits earlier this fall by shorting, or betting against, natural-gas prices using futures contracts traded on the New York Mercantile Exchange. Like many futures firms, Mr. Smith says Superfund bases its trades on price trends and other data analysis, rather than speculative hunches. To further limit risk, it also caps each bet at 1 percent of the fund's total holdings.

In the case of natural gas, Superfund's short position proved correct, as inventories rose, the Atlantic hurricane season produced no Katrina-like catastrophe and natural-gas prices fell. Prices were also hurt by heavy selling from the doomed hedge fund Amaranth Advisors, which in September lost more than $6 billion, largely from unwinding unprofitable bullish energy bets.

Natural-gas futures plunged more than 30 percent from the start of September to their annual lows late in the month, around $4 per million British thermal units. Gas futures have since recouped some of those losses but remain down 34 percent so far this year, at $7.409 per million BTUs through Friday.

Despite the financial boon for short sellers during Amaranth's meltdown, some on Wall Street worry that such headline-grabbing scandals put everyday investors ill at ease regarding commodities investing in general, perhaps keeping some away from the market.

Russell Andersson, vice president of the online exchange HedgeStreet Inc., which offers energy and metals contracts, says price weakness tends to turn off everyday investors, whether those moves are a result of scandal or straightforward supply-and-demand issues.

"The perception among retail traders is that the long, definable trends are over," which means that a steady bull market for commodities is no longer a sure bet, says Mr. Andersson, whose firm recently garnered a minority investment from the Chicago Board Options Exchange and began a marketing campaign aimed at everyday investors.

He says HedgeStreet, of San Mateo, Calif., has fewer than 10,000 users so far, but he believes many of those traders have become savvy enough to trade profitably even if the downtrend in commodities persists.

So what are the good short bets going forward? So what are the good short bets going forward? Whatever commodities whose value stands to plunge. The various energy products are possible candidates. To make a bet against the entire sector, investors could short the broadbased Dow Jones-AIG Commodity Index. So far this year, the index is off about 1.7 percent at 168.323, hurt mostly by weaker energy prices. If the indicator stays in the red through the end of the year, it will snap a four-year winning streak, during which the index nearly doubled.

For investors who aren't comfortable shorting, and would rather make traditional investments, analysts say there are still some areas of strength in the sector. Gold prices have jumped about 19 percent this year so far, to $615 a troy ounce as of Friday on Nymex's Comex division, partly because of weakness in the U.S. dollar.

Gold traditionally moves in the opposite direction of the dollar because many traders view it as an alternative, widely accepted store of financial value during periods when people lose confidence in paper currency. If the U.S. central bank proceeds to cut interest rates sometime next year, as many analysts expect, that would effectively increase the money supply, which in turn would likely push the dollar lower and boost gold further.

Also, copper is up 39 percent, and silver is up 47 percent so far this year because of continuing strength in industrial demand from China and other emerging markets.

In a recent note to clients, Credit Suisse Group economist Kathleen Stephansen said that the balance between global supply and demand for various commodities -- highlighted by China's need for crude oil, iron ore, nickel, zinc and copper -- should remain tight next year, propping up prices. If the Fed begins cutting interest rates next year, that could eventually stimulate U.S. demand for raw materials, weaken the dollar and make exports like U.S. grains more competitive in overseas markets. Such moves by the Fed would lower borrowing costs, which traditionally encourages construction and other industrial activity.