Just as we examine companies each week that may be rising past their fair value, we can also find companies potentially trading at bargain prices. While many investors would rather have nothing to do with companies tipping the scales at 52-week lows, I think it makes a lot of sense to determine whether the market has overreacted to the downside, just as we often do when the market reacts to the upside.

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

The last optimists have left the building
When there are literally no reasons left to own a stock, that's generally when I'm digging deep, looking for a reason to buy. With regard to biotech redheaded stepchild Dendreon (Nasdaq: DNDN), I finally see reasons to be bullish.

Dendreon itself has seen failures on multiple fronts. The product launch of Provenge, its infusion targeted at treating late-stage prostate cancer, went miserably, with physicians shying away from prescribing the treatment due to its costly $93,000 price tag. Even worse, two drugs currently in development could further disrupt Dendreon's already shaky sales growth. Johnson & Johnson's (NYSE: JNJ) Zytiga was shown in studies to be more effective at extending patients' life and quality of life as compared to Provenge (although further data is pending), while Medivation's (Nasdaq: MDVN) enzalutamide has shown statistically strong life-extending results with minimal side effects in trials.

With so much negativity piled up on Dendreon, it's my contention that it will be forced to do two things: marginally drop the price of its treatment in order to compete with Zytiga's $5,500 monthly cost and consider allying itself for further clinical studies to be used in combination with these experimental therapies. Rather than positioning itself as a stand-alone therapy, Dendreon could find a huge market in combination therapies. Dendreon has ample cash to conduct further studies and appears to have a good risk-reward balance at this level.

IP-Oh, no!
If you thought Facebook shareholders were having a hard go of things since its public debut, then be glad you're not a shareholder of travel and business accessories maker Tumi Holdings (NYSE: TUMI), whose shares have spiraled steadily since its IPO. Brand-name accessory stocks have generally been strong performers until recently, so it's a bit confusing that Tumi shares have taken such a rapid dive. Fundamentally, I will admit, it isn't the cheapest company at 42 times trailing-12-month earnings, but it has a lot going for it.

Tumi's first-quarter report detailed a 16.9% increase in direct-to-consumer North American comparable-store sales. Weakness abroad caused its international comparable-store sales to fall by 1.6%, including e-commerce sales. Despite the mixed results -- which aren't that shocking, given the weakness we've witnessed in European spending -- the company reversed a marginal year-ago loss into a $2.9 million quarterly profit. Overall, net sales increased 21.4% as Tumi added 13 stores over the past year.

What I really like about Tumi is the room it has to grow internationally and the strength behind its easily recognizable product label. Tumi slides perfectly into most consumers' comfort zones for spending (not too cheap, not too expensive) and sells products that professionals constantly are demanding. It's an intriguing long-term play.

Good golly, Miss Molycorp!
After more than a year of being pessimistic on rare-earth metals, I'm ready to change my tune as pessimism in the sector begins to build. Molycorp (NYSE: MCP), a rare-earth minerals miner that I've maintained a CAPScall of underperform on for months (a call I'm currently up 53 points on), looks like it has paid its dues. I'm now ready to close that underperform pick and break out my bullish pom-poms on Molycorp. (Trust me -- it's not as pretty of a sight as you might think.)

There are viable reasons to be concerned about Molycorp's growth over the next few quarters, as the Fool's Travis Hoium has pointed out. Although revenue and profits are rising dramatically, the price of the rare-earth metals that Molycorp mines are well off their highs. For now, the year-over-year comparisons are showing huge growth, but a year from now these comparisons will be much tougher to beat.

Still, Molycorp remains one of only two publicly traded and fully operational rare-earth miners (Lynas being the other), and it will hold on to that unique advantage for many years to come, considering that Avalon Rare Metals and Rare Element Resources are still years from having their mines up and running. The profits being produced here aren't small, either, even if rare-earth prices are falling. With a stranglehold on the U.S. market and a value of just seven times forward earnings, Molycorp shares are worth a shot here.

Foolish roundup
This week, it's all about being greedy when others are fearful. Shareholders of Dendreon, Tumi, and Molycorp are running for the hills and looking for a reason to sell their stock. As for me, that's the perfect recipe to be on the prowl for great values. 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.

In the meantime, consider adding these potential winners to your free and personalized watchlist -- and get your own personal copy of our special report, "The Motley Fool's Top Stock for 2012," to see which company our chief investment officer has dubbed the "Costco of Latin America." Best of all, this report is completely free, so don't miss out!