With stock markets soaring, it's getting increasingly difficult to find good investments that offer decent value. All too often, investors chasing hot investments pay top dollar only to find that they've gotten in right at the end of a bull market.

But if you're willing to look a little harder, you can find some investment bargains, even as stocks soar to new multi-year highs. One great place to watch for value is in the closed-end fund market.

Why you need closed-ends
Lately, exchange-traded funds have been all the rage among investors. With hundreds of ETFs available to meet just about any investing need you could imagine, ETFs are easy to use, readily available from any brokerage company, and combine both transparency and low costs to give you the ability to pinpoint exactly the investment exposure you want.

But closed-end funds have been around a lot longer than ETFs, and they carry many of the same advantages. They trade whenever the market is open, giving them a liquidity advantage over traditional mutual funds that only accept buys and sells once each day. And in fact, closed-ends have a special trait that can actually make them better investments than ETFs -- if you're willing to be patient and can capitalize on opportunities when they arise.

Supply and demand
If you're not familiar with closed-end funds, the most surprising thing about them is that they only make a limited number of shares available to investors. Unlike ETFs, you can't go to the fund company and arrange to have new shares created, nor can you present a certain number of shares and ask the fund company to redeem them in cash or securities. Except for occasional share buybacks and secondary offerings, closed-ends keep a constant number of shares outstanding.

That makes prices of closed-end funds much more connected to supply and demand than to the net asset value of the investments the funds hold. Closed-ends in hot sectors often trade at a premium to their NAV. For instance, with precious metals at or near highs, closed-end Central Fund of Canada (AMEX: CEF) has traded at a premium for years, while Sprott Physical Gold Trust (NYSE: PHYS) and Sprott Physical Silver Trust also fetch prices above the value of their holdings.

But price differentials work both ways. Sometimes, you can find promising investments more cheaply than you could get them from regular mutual funds or ETFs. Here are five closed-ends that trade at substantial discounts that deserve a closer look:

Boulder Growth & Income (NYSE: BIF) -- 15.84% discount
Boulder is a stock fund that offers an interesting deal: It has more than a quarter of its assets invested in Berkshire Hathaway, with other large positions in well-known blue chip stocks. The fund also has a large cash position. If you want exposure to Berkshire at a 16% discount, Boulder may have just what you're looking for.

Royce Value Trust (NYSE: RVT) -- 13.76% discount
Chuck Royce has a solid reputation for small-cap investing, with several traditional mutual funds that have performed quite well. Yet investors can get Royce's expertise at 14% off through this closed-end fund, which owns plenty of promising small-cap stocks.

Adams Express (NYSE: ADX); 13.78% discount
This closed-end fund has been around for decades, and its holdings list includes cream-of-the-crop U.S. stocks. Yet you can buy shares of the closed-end for almost 14% less than you'd pay for underlying stocks in the portfolio.

Petroleum & Resources (NYSE: PEO); 11.97% discount
Sharing a manager from Adams Express, this closed-end focuses on energy and natural resource companies. Adams Express even owns shares of this closed-end, giving Adams investors a double discount. With energy stocks soaring, finding this fund at a discount is an unexpected surprise.

ASA Gold & Precious Metals (NYSE: ASA), 8.38% discount
Just as finding Petroleum & Resources at a discount seems strange during an oil boom, it's shocking to find a precious metals fund trading at a discount. But ASA owns shares of well-known stocks like Barrick Gold and Goldcorp; shares you could buy on your own, but through ASA, you get an 8%+ discount.

Take a closer look
Don't treat these discounts as a surefire road to quick profits. There's no guarantee that supply and demand characteristics will return to normal in any reasonable timeframe. So even though you may buy shares at a discount now, you may have to sell them at an even bigger discount down the road.

But for many, the bargains available in closed-end funds are worth that risk. At the very least, you should add them to your watchlist to keep tabs on whether they may be right for you.

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Tune in every Monday and Wednesday for Dan's columns on retirement, investing, and personal finance.