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 companies' 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.

Keeping it clean
It's getting harder and harder to find companies trading anywhere near their 52-week lows these days, but few offer as exciting a future as environmental and industrial waste and recycling company Clean Harbors (NYSE:CLH).

Perhaps nothing put this company on the map in recent years more than Hurricane Katrina and the Gulf of Mexico Macondo oil spill, which put the spotlight on the company's environmental cleaning efforts. In addition to providing these land and water environmental clean-up services, Clean Harbors recently completed the acquisition of Safety-Kleen, which allowed it to become a recycler and refiner of used oil, as well as routine environmental service provider to the oil industry.

Without even having to look at Clean Harbors' latest earnings report, you can likely already see the value of its services. Oil spills, natural disasters caused by weather and earthquakes, and routine environmental needs caused by fracking and other industrial activities give Clean Harbors a nearly steady stream of business and cash flow, as well as pricing power!

We can visibly see this success in Clean Harbors' results, which, in addition to its Safety-Kleen acquisition, yielded a 70% increase in revenue and a 185% jump in net income for the third quarter. Clean Harbors might appear a bit pricey at 20 times forward earnings, but given its niche environmental services and size, I don't have any problem paying a premium for its services.

Finally worth a look
As someone who worked in retail for the better part of a decade, I fully understand how fleeting hot trends can be in the fashion world and how quickly a sizzling IPO can fade.

For some time now, I've been negative on Francesca's Holdings (OTC:FRAN), a specialty boutique that sells apparel, jewelry, and accessories, because of its willy nilly expansionary tactics and unsustainable same-store sales growth. In the company's most recent quarterly report, Francesca's reported a 3% decline in same-store sales as compared to a year-over-year gain of 17% in the year-ago period despite delivering an 11% improvement in profits. In other words, the company is seeing new store growth, but existing stores are struggling right along with other retailers, especially with regard to jewelry and other accessories. It also reported a 17% decline in profits as it spends heavily on expansion in order to bolster its image. 

While these results weren't anything to write home about, with its share price now roughly halved from its highs set in May, I feel it's looking quite attractive.

For one, Francesca's has been able to fund its new stores with existing cash on hand and operating cash flow. The key point here being that it carries no debt, and thus has no liquidity concerns if we head into another recession. Another factor to consider here is that the consumer is being very wary of their spending habits this holiday season as is evidenced by the tepid back-to-school season. With that being said, Francesca's offers an array of discounted and varied merchandise that should fare well in attracting cost-conscious mall shoppers. Finally, the valuation just makes sense. At less than 13 times forward earnings and with an expected double-digit growth rate, I feel shares could be a bargain at these levels.

The new near-necessity product
The technology sector is a breeding ground for rapid growth rates, but it's also one of the most susceptible sectors when it comes to cycles. Few tech companies are able to thwart the inevitable slowdown in spending that occurs now and then, save for maybe one subsector: network security.

Over the latter half of the past decade, cloud and PC-based network security companies have thrived as hackers and viruses have become more sophisticated and complex. I would venture so far as to say that network security is no longer an optional piece of software for a business -- it's a near necessity! That's why I feel Fortinet (NASDAQ:FTNT), a provider of consumer and enterprise-based Internet and networking security solutions, could be a good fit for your portfolio.

Fortinet has been knocked off the horse in recent weeks because of the announcement of the departure of its chief financial officer and chief operating officer, Ahmed Rubaie. Obviously, the loss of a high-ranking individual could throw a monkey wrench into its long-term plans or cause it to deviate from its current path of growth. The way I see it, though, is that Fortinet simply needs to remain innovative and the demand for security solutions will take care of itself.

Even with the negative effects of a government shutdown and the potential for higher health-care costs to increase enterprise expenses, Fortinet still managed to boost revenue by 14% in the third quarter with a 20% increase in service revenue, which provides beefier margins. Furthermore, deferred revenue increased 18%, meaning that its contracted business is a bit stronger than what's actually being reported on an amortized basis. In addition to ending the quarter with $841 million in cash and no debt, it just yesterday announced a share repurchase program totaling up to $200 million. Share repurchases won't put money directly into shareholders' pockets, but it does reduce the amount of shares outstanding, which can help EPS. 

This is another case where I believe Wall Street is far too focused on three months from now and ignoring where Fortinet will be three years from now.

Foolish roundup
This week was really all about redemption for three stocks that were all once very expensive and now seem quite attractive given their long-term business model and cash flow-generating capabilities. Clean Harbors and Fortinet offer a near-necessity demand product that's quite inelastic to pricing pressures while Francesca's simply has the right pricing and inventory strategy to cater to a cost-conscious consumer.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.