Just as we examine companies each week that may be rising past their fair values, we can also find companies trading at what may be bargain prices. While many investors would rather have nothing to do with companies wallowing at 52-week lows, I think it makes a lot of sense to determine whether the market has overreacted to a company's bad news, just as we often do when the market reacts to good news.

Here's a look at three fallen angels trading near their 52-week lows that could be worth buying.

Don't hate this basic necessity
It's true that it's been a nightmarish past two years for coal manufacturers. Low natural-gas prices coerced a number of electric utilities in the U.S. to make the switch from coal-fired to natural-gas-burning facilities, while China's erratic growth rate caused a slowdown in coal demand, leading to a glut in supply and a freefall in prices. The end result has been losses across much of the sector.

However, if there's one region of the world where coal continues to make a lot of sense, it's Asia. India and China are only in their infancy in terms of industrialization, and the need for energy demand is going to grow like a weed in these two highly populated countries. This means China's Yanzhou Coal Mining Co. (NYSE:YZC) just might be the perfect position.

One obvious benefit Yanzhou possesses is that it's based in China! While U.S. producers like Arch Coal (OTC:ACIIQ) are clamoring to set up export agreements from the West Coast and Gulf Coast ports to China in order to improve their leverage and sales, Yanzhou has a front seat to what should remain robust demand on the heels of a nearly 8% GDP growth rate. It would only be logical that domestic Chinese utilities are going to favor what should be cheaper coal from Yanzhou.

Yanzhou should also begin to see stabilizing prices given the basic necessity nature of the coal business. While China is committed to reducing its carbon footprint, the energy demands of its 1 billion-plus citizens are simply too great to be met by solar and other alternative energies alone. This means coal will continues to play a vital role in China's energy production for years to come. Even within the U.S., coal still accounted for 37% of all electricity production in 2012. This reliance on coal should ultimately help to put a floor under coal prices.

With Yanzhou valued at close to half of its book value but also carrying $5.65 billion in net debt, I feel the risk/reward ratio has finally swung back in favor of the optimists. It may not be a smooth trip higher, but I suspect China's superior growth prospects will drag Yanzhou out of its rut in short order.

This buyout makes sense
Despite being in a sector that rarely sees much volatility, diversified energy delivery company UIL Holdings (UNKNOWN:UIL.DL) had a wild last week, ending lower by nearly 9%. The reason for the drop was the announcement that it would be purchasing Philadelphia Gas Works from the city of Philadelphia for $1.86 billion.

The skepticism that has surrounded this deal is twofold. First, there were 33 separate bids entered for PGW, and UIL came out on top. Therefore some investors would assume that UIL overpaid to get its hands on PGW's more than 1.2 million customers, of which nearly 900,000 use natural gas. The other concern here would be the need to work with PGW's labor union. UIL, in its press release, noted that it would be honoring the existing collective-bargaining agreement in place with PGW Operations' union, but there's always the risk that this ownership transition could create a ripple between management and labor.

Despite the 9% drop, though, I feel this could be the perfect opportunity to take a nibble of UIL Holdings. To begin with, UIL points out that the transaction is expected to be immediately accretive to its EPS and free cash flow. Furthermore, PGW's infrastructure is going to be crucial in UIL's efforts to increase and improve its infrastructure surrounding the highly coveted and natural-gas-rich Marcellus and Utica shale formations. Although the move will push UIL's customer profile more toward the natural-gas side of the equation, a rebound in natural-gas prices since 2012 coupled with a growing need for non-foreign energy should help UIL over the long haul.

At the moment UIL is valued at only 14 times forward earnings and is boasting a dividend yield of 5%. Keep in mind, this forward P/E hasn't yet factored in the expected EPS benefits from the PGW transaction, assuming it's approved. All told, UIL looks like it's been unfairly trounced after last week's purchase, and I'd suggest that income-seeking and risk-averse investors give it a closer look here.

Is this a perfect buyout candidate?
Lastly, I want to highlight health care information systems developer Quality Systems (NASDAQ:NXGN), which has struggled over the past year following three earnings misses over the past four quarters.

In the third quarter, for instance, Quality Systems reported a disappointing 5% decline in revenue from the year-ago quarter, while adjusted EPS, which excludes an impairment charge in its hospital solution division, fell 62% to $0.11. The onus of blame continues to fall on weak bookings in its hospital service segment.

However, despite this weakness, I would contend that Quality Systems could soon stand out as a perfect takeover target. Understand that when I say this I have no inside information, nor has there been any shred of evidence to suggest that Quality Systems is going to get purchased. But what it does have are some factors which could make it very attractive to a possible suitor.

For one, Quality Systems has $94 million in cash with absolutely no debt. For a possible buyer it's always great when you can acquire a company without having to deal with its preexisting liabilities.

Perhaps the bigger allure, though, is that hospitals and clinics are increasingly moving toward revenue cycle management software and electronic-health records to help streamline their business and reduce their costs in the wake of the uncertain spending landscape that Obamacare has brought about. Quality Systems, as a developer of RCM and EHR software, should be a major beneficiary of this movement over the next couple of years.

While it's struggling now, it's not as if Quality Systems isn't profitable. The company is valued at 22 times forward earnings, and I suspect it has the potential to grow in the high single digits if it can get its hospital segment back on track. Now that it's well off its highs, I believe any further downside could put a big bull's-eye on Quality Systems' shares.