Martin Zweig was one of the market visionaries who called Black Monday in 1987 and cashed in on its eventual recovery. However, the weight of yesterday's guru seems feathery these days. Zweig Fund (NYSE:ZF), a closed-end fund that he co-manages, is trading at a 13% discount to its actual net assets. Its top holdings include quality names like Dell Computer (NASDAQ:DELL), Pfizer (NYSE:PFE), and Cisco Systems (NASDAQ:CSCO). So far, so good -- but why so cheap?

If buying a no-load mutual fund is preferable to the loaded variety, what does that say for closed-end funds trading for less than they're worth? Yesterday, we covered a few closed-end funds, such as Zweig's, that trade at significant discounts. The fact that many of these funds seem to perpetually trade at marked down prices may make the benefit of buying a buck's worth of assets for 85 cents seemingly negligible, but that's not the only advantage to these funds.

Closed-end funds are not to be confused with open-end funds that are closed to new investors. Closed-end funds are simply exchange-traded vehicles. Because they have a set number of shares it creates a major advantage for the money manager. There are no worries about raising cash for redemptions or letting cash pile too high with new purchases. In theory, that should produce superior results. You also won't find any pesky 12b-1 marketing fees.

Our new Motley Fool Champion Funds is seeking out market-thumping mutual funds. Closed-end funds tack on a second layer of opportunity. Investors seeking out quality funds can also possibly buy in at a discount.

Another advantage to closed-end funds is that because they trade throughout the day, they are less likely to fall into the trap of the disingenuous open-end funds that accepted shareholder-damaging late trades from greedy hedge funds.

So don't ignore the many mutual fund possibilities out there. They come in all shapes, sizes and -- apparently -- prices.

Are closed-end funds riskier than open-end funds? What are your expectations for Motley Fool Champion Funds ? All this and more -- in the Mutual Funds discussion board. Only on

Longtime Fool contributor Rick Munarriz prefers open signs to closed ones -- but doesn't necessarily feel the same way when it comes to investing. However, he does not own shares in any company mentioned in this story.