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.

The advertising wave of the future
"Yuck" would be a good word to describe the reaction to digital advertising solutions provider YuMe's (NYSE: YUME) fourth-quarter results, released after the bell this past Thursday.

For the quarter, YuMe reported a 19% increase in revenue to $54 million, a 30-basis-point decline in year-over-year gross margin to 48.1%, and net income of $0.16 per share compared to $0.06 in the prior year. Where the wheels fell off the bus was in the company's full-year fiscal 2014 forecast, which calls for $190 million-$200 million in revenue on $2 million-$8 million in adjusted EBITDA. By comparison, the Street had anticipated $203.6 million in revenue for the full year -- thus the shellacking shares took at the end of the week.

However, instead of playing ostrich and burying your head in the sand, I believe this dip could represent an intriguing buying opportunity for tech-savvy and aggressive investors who are looking for ways to take advantage of the mobile advertising revolution.

Despite the dip, YuMe managed to increase its number of clients by 29% to 580 during fiscal 2013, although the revenue collected per customer dipped less than 1% to $255,000. This could signal tighter ad spending, but it could also simply be that new customers are dipping their toes in the water with the relatively young YuMe rather than diving right in, which isn't necessarily a bad thing.

What I believe investors should note are two primary factors. One, YuMe is already profitable. Sure, it's only marginally profitable, but it wouldn't take more than simple cost-cutting -- as opposed to aggressive marketing and expansion efforts -- to bring its profit in line with its current price. Based on its forward P/E of 25 and its projected revenue growth rate of 15%-20%, I'd say there's room for upside potential.

The other factor is that there's still a lot of jockeying to be done when it comes to mobile advertising. Mobile audience targeting is still in its relative infancy, with few businesses having much figured out. This means revenue recognition may be a bit "lumpy" at times, but the overall trend remains that consumers are utilizing their mobile gadgets more and more. YuMe has a solid cash foundation of $49.5 million in net cash and plenty of growth in its sales. In other words, the ingredients for success are there; it's whether or not they'll now mesh together that remains to be seen.

Rethink purchase?
Great companies don't often just fall into your lap, but the recent swoon in telecommunications giant AT&T (T -1.37%) has me thinking that income-seeking and risk-averse investors now have the perfect entry point into what has practically become a basic necessity product: the phone.

AT&T shares have been hit hard since May, losing about 20% of their value (more than $36 billion) because of a more competitive telecom environment spurred through mergers and acquisitions, as well as the need to spend heavily on next-generation 4G LTE networks to catch up to the likes of Verizon, which has as many large U.S. cities covered by 4G LTE as all its peers combined! Coupled with AT&T's purchase of the money-losing and much-maligned Leap Wireless (NASDAQ: LEAP) for $1.4 billion in order to gain more spectrum, it's not too tough to see why its shares have moved lower.

But there's another tale to tell here. For one, AT&T provides what is pretty much considered a basic necessity product. Consumers will cancel their gym memberships, stop eating out, and cut others corners long before they give up their smartphone. What this does is give AT&T a fairly predictable rate of cash flow quarter-to-quarter, and incredible pricing power. It also allows the company to use its brand power to go after its rivals, such as its recent ploy to lure T-Mobile (TMUS -0.08%) subscribers to its network by agreeing to pay a customers' contract termination fee. Not to mention that AT&T has introduced early upgrade options via its Next program, which I actually took advantage of two weeks ago due to a number of glitches in my current smartphone.

The real allure, though, may be in AT&T's nearly 6% yield. Because its cash flow remains so consistent, and because the product is viewed as a necessity, there's little reason to believe that AT&T's dividend is going to drop anytime soon. With nearly $35 billion in operating cash flow generated over the trailing 12 months, I'd suggest it's time to look at Ma Bell as a buy once again.

Nothing could be finer
Last, but certainly not least, we have CVR Refining (CVRR), a master-limited partnership that owns crude-refining facilities and pipeline logistics assets in the Mid-Continental United States.

As has been the case with much of the oil industry of late, CVR Refining has struggled. Its shares are down roughly 40% from its 52-week high as crack spreads have weakened and crude oil demand waned toward the end of last year. The end result was a weak fourth-quarter, which saw CVR report a net loss of $110.2 million compared to a profit of $54.6 million in the year-ago period. Despite what can only be described as a miserable quarter, I see the potential for a rebound in this stock sooner rather than later.

One factor that has me intrigued is the simple fact that the price-per-barrel differential between West Texas Intermediate and Brent Crude has narrowed dramatically from where it was in November when the spread was nearly $20/barrel. At just $7/barrel, domestic producers are far less likely to ship their crude from the Bakken and other Williston Basin territories to the Gulf to be shipped overseas in order to take advantage of Brent pricing. Instead, domestic producers are more likely to send their crude to Cushing and right into the hands of CVR and its peers. This means the demand swoon we witnessed last quarter will likely abate by the midpoint of 2014.

Another factor to consider, as Motley Fool energy guru Aimee Duffy notes, is that crack spreads due to gasoline pricing has improved in recent months, which could lead to better results in the coming quarter. As Aimee points out, earnings reports are looking back at crack spreads from months ago while the market and investors remain focused on current crack spreads. Simply put, it means that CVR's bad quarter is already a thing of the past.

Finally, keep in mind that as an MLP CVR Refining gets preferential tax treatment that results in a whopper of a dividend for shareholders. Based on its latest payout of $0.45 per share, CVR is on pace to divvy out a Treasury-thumping 8.6% yield in 2014. Perhaps it's time to give this refiner another look?