Just as we examine companies each week that may be rising past their fair value, 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.

Leasing for the wave of the future
Believe it or not, there is a recent IPO that has me thoroughly excited, as it's smack-dab in the middle of a rapidly growing growth opportunity -- yet surprisingly, it doesn't have a lot to do with the technology behind the movement.

The company in question is QTS Realty Trust (QTS), an owner and leaser of office space for enterprise customers to set up their data centers. The build-out of large data centers allowing for the seamless integration of multiple applications from the cloud will be a monumental spending project for many enterprise customers over the next decade. Understanding this, QTS has been buying up office space to house these data centers, which it can then rent out for a handsome profit with high margins.

The first concern most people would have with a company like QTS is that it either hasn't been around long enough to know what it's doing or has buried itself in debt from real-estate purchases. The good news is that both aspects here are covered. QTS has owned or leased seven of its 10 properties for five or more years, signaling that it understands the business and knows how to attract quality tenants. Further, when QTS went public recently, it was able to generate significant capital and pay off most of a revolving line of credit.

The proof is in the pudding if you look at QTS' third-quarter results, released last week. Revenue was up 46% year over year, rental income was moving higher, monthly recurring revenue was up 29%, and operating funds from operations were up a whopping 151%! Furthermore, rental occupancy is only at 81% prior to its Dallas facility opening, so there's still a lot of room for top- and bottom-line expansion. This looks like a potentially genius way to play the data center revolution and, at roughly 10 times forward earnings, I would certainly suggest a deeper dig.

An overdone sell-off
That chill you feel isn't winter around the corner -- it's because hell just froze over and I'm about to suggest taking a closer look at an alternative-energy components manufacturer, Fuel Systems Solutions (NASDAQ: FSYS).

Historically speaking, alternative-energy companies aren't my cup of tea. Many have demonstrated a lot of promise on paper, but few have delivered tangible results. Fuel Systems Solutions, on the other hand, has delivered solid results, but the market seems unwilling to cut it the same slack that I see some of its peers getting.

In FSS' most recent quarter, it delivered a 9% increase in revenue to $97.6 million and profit of $0.05 per share, reversing a $0.03 year-ago loss. However, it also warned that tougher competition and overseas austerity measures in Europe are forcing it to cut costs and remain cautious about its near-term outlook. It therefore guided investors toward the low end of its previous $400 million to $420 million full-year sales guidance compared to Wall Street's $416 million consensus prior to the report. Still, I see plenty of positives.

To begin with, how many alternative-energy companies can claim to be profitable? Not too many, by my count. FSS is profitable, albeit with a forward P/E closing in on 50 after its most recent earnings warning. What interests me is that while many alternative-energy components suppliers cue in on the personal automotive market, FSS is also making its home as a supplier to the heavy-duty trucking, industrial, and bus industry, which is where a move toward natural-gas-powered engines makes a lot of sense. Public transportation and heavy-duty equipment have been fairly quick to make the transition, offering up a world of opportunity for FSS while many of its peers struggle with the consumer market, which is more resistant to change.

Overall, FSS's report did warrant some caution among investors, but I feel emotions got the better of nearly everyone over the past week. With moderate cost-cutting and one or two quarters to put near-term order delays in the rearview mirror, FSS will be right back on the growth path.

Building your future
Continuing my theme of surprises this week, the last opportunity I'd suggest looking into is the PowerShares Emerging Markets Infrastructure ETF (NYSEMKT: PXR). This ETF purchases companies that operate in emerging markets (surprise, right?) and are involved in activities like construction, construction materials and machinery, heavy-duty machinery, engineering, and steelmaking.

Right now, it's not difficult to understand why this ETF is trudging along near a 52-week low. The steel market has been glutted with excess supply, and Caterpillar (CAT 1.58%), one of the most renowned heavy-duty machine manufacturers, recently lowered its revenue and profit forecast for a third-time this year, with little global visibility in sight as to when the weakness would end. The downside of an investment in this ETF is that you are going to deal with exposure to some larger emerging market countries like China, where mining activity is weak (Caterpillar is actually one of the fund's top holdings). But there are other notable reasons why this could wind up being a great long-term investment.

One aspect to consider is that emerging market countries often grow independently of the industrialized countries in the world and offer higher growth rates than first-world countries. This means an ETF like this can provide stability when U.S. and European construction growth is minimal or even negative.

Buying here would also net you what I believe could be a basket of construction companies at an excellent price. Emotional traders have absolutely pummeled commodity-based construction companies, which could allow you to swoop in when the overall ETF sports a P/E of just 13 and a yield of 1.3%.

Finally, the construction and commodity industry is a cyclical creature. It's always tough and/or impossible to call a top or bottom in the sector, but pessimism has been growing for multiple quarters now. At some point soon I think the tide on commodities is going to turn, which is going to bode well for this basket of companies.

Foolish roundup
This week was really all about stepping outside of the box and into uncharted territory. Sometimes the best deals can be found by looking in areas where you often criticize, rather than allowing your emotions to get in the way.

I'm so confident that these three names will bounce off their lows that I'm going to make a CAPScall of outperform on each one.