Your stock just took a nosedive -- but don't panic. First, let's see whether it had good reason to fall. Sometimes, panic-fueled drops can make excellent buying opportunities. Here's the latest crop of cratered stocks that could provide a possibility for profit:

Stock

CAPS Rating
(out of 5)

Tuesday's Change

Dex One (Nasdaq: DEXO)*(13.5%)
Acura Pharmaceuticals (Nasdaq: ACUR)*(9.3%)
Pandora Media (NYSE: P)*(7.6%)

Markets staged their fourth straight up day following a week of dreary movements lower as they warmed up to the notion Greece will adopt austerity measures. The Dow Jones index rose 109 points, or almost 1%; stocks that went down by larger percentages are pretty big deals.

The devil's in the details
Don't worry too much about the drop in Dex One's stock, it's just investors taking some profits off the table after it rocketed some 65% higher the day before on an AdWords agreement with Google. For a company that emerged from bankruptcy only last year, it was a welcome opportunity to book some gains.

Dex One is the former Yellow Pages publishing king R.H. Donnelley, which back in its heyday, published Yellow Pages, white pages, and various niche vertical directories. Think of it as the original local search provider.

While it still publishes those directories -- harking all the way back to 1886 in Chicago, when Reuben H. Donnelley published what is claimed to be the first telephone directory -- the print version is secondary to the online option, which is why the Google agreement is key for Dex. Local search has gotten hot, with ReachLocal (Nasdaq: RLOC), Local.com (Nasdaq: LOCM), and many more flooding the space.

But the agreement is not unique. A couple of months back, ReachLocal was soaring on the announcement of similar news. Investors were likely smart to take some of their profits off the table. As CAPS member ValueSlant points out, becoming a Google Certified Partner is more akin to being a reseller then being invited into an exclusive club. Dex One is going to have a tough road before it:

Dex One appears to have zero competitive advantage in the online space that they are looking to for growth in order to offset the continued print ad declines. They are in a race against their declining cash flows to pay down the debt to the point where they will be able to refinance in 2014.

Dex is looking for the deal to help it achieve its goal of 30% of revenues by the end of 2012 coming from digital sources, up from 10% in 2010. Keep an eye on whether Dex One can achieve its goals by adding its stock to the Fool's portfolio tracker, where all the news and analysis is brought together in one place.

Don't feel a thing
Acura Pharmaceuticals was another stock giving up some meteoric gains achieved the previous day. On Monday, the pharmaceutical's stock jumped 16% (at one point it was up more than 75%) on news the FDA had approved Oxecta, its abuse-resistant formulation of the powerful painkiller oxycodone, which it's developing with Pfizer (NYSE: PFE).

The FDA is requiring all opioid drugmakers to come up with a plan to limit the abuse of their drugs. Addicts have shown an incredible aptitude for converting OxyContin (the brand name of oxycodone) into more potent drugs by extracting the active compounds from it. Pfizer has been working with Pain Therapeutics to bring to market Remoxy, another abuse-resistant formulation, but recently announced some manufacturing issues that analysts believe may hinder immediate FDA approval.

Thus the Oxecta achievement is just as important for Pfizer as it is for Acura. There's an estimated $100 million market to tap (analysts think Remoxy can rake in $500 million) so the approval gives Acura some breathing room to ramp up sales.

There was a lot of skepticism built into Acura's stock, perhaps on the basis of Remoxy's bigger market, but less than two-thirds of the CAPS members rating the pharmaceutical believe it will outperform the market indexes, while 70% of the All-Stars weighing in don't think it will pass muster. Let us know on the Acura Pharmaceuticals CAPS page whether you think the drugmaker will dull the pain for investors.

Don't open that box
It seems almost too easy to call Pandora's decline. While some unfortunate sap got stuck with the Internet radio stock at $24 a share shortly after its IPO, no one has really been tuning in to its valuation, and the stock is well below its debut price and is nearly sliced in half from that intraday high.

Yet Pandora is not worthless, as the Fool's Anders Bylund points out. In fact, it can even offer a viable challenge to both Apple and Sirius XM Radio (Nasdaq: SIRI): "I still think that's true because Pandora out-Apples Apple itself in the user friendliness department, and that's worth a lot," wrote Anders. But it still carries a lot of baggage, so he'll wait before buying in.

Is Pandora worth buying, or, like its mythical namesake, an investment poised to unleash evil into your portfolio. Let us know in the comments section below and add its stock to the Fool's free portfolio tracker.

Ready for a resurrection
Just because your stock has taken a beating doesn't mean it's going to roll over and die. Markets are known for overreacting. A closer look on Motley Fool CAPS at what's happened to your stock can give you an edge over other investors who just react to the market's lead. You can decide for yourself whether it's ready to come back from the dead.