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)

Monday's Change

Arena Pharmaceuticals (Nasdaq: ARNA)

**

(6.5%)

Oilsands Quest (NYSE: BQI)

****

(10.0%)

STR Holdings (Nasdaq: STRI)

***

(7.3%)

The devil's in the details
On a day when the market rose 1.4%, yesterday's declines are big deals, yet there was no specific news to account for some companies to run in the opposite direction. STR Holdings, a maker of encapsulants for solar panel manufacturers, is an example. First Solar (Nasdaq: FSLR), its top customer accounting for more than a quarter of total 2009 revenues, was up almost $1 per share yesterday while SunPower (Nasdaq: SPWRA) was up nearly 4% on the day.

As investors in the solar industry know, PV panels can be made in any number of ways. There's mono- and polycrystalline silicon for silicon cells, and amorphous silicon, gallium arsenide, copper indium gallium selenide, and cadmium telluride for thin-film cells. But regardless of the technology used, all the manufacturers need encapsulants to protect the circuitry, and STR Holdings is the company most of them turn to. If the solar industry is going to grow, you can almost guarantee STR will be growing with it.

I've added STR Holdings to My Watchlist page to get all the Foolish news and analysis about this solar specialist aggregated so that I can keep track of what's happening. I've also marked it to outperform the broad market averages on the STR Holdings CAPS page. Join me there and let me know your views on this key supplier to the solar industry.

The sky's not the limit
Similarly, there was no news that should have caused Oilsands Quest to drop as it did. It wasn't that long ago (less than two weeks really) we were remarking on the surge in its share price, but it has been on a bit of a roller-coaster ride of late. Last week, it was also bouncing up and down, sometimes by significant percentages. For penny stocks like Oilsands, particularly ones undergoing "strategic reviews" and looking to sell themselves to the highest bidder, it's not unexpected.

The CAPS community remains hopeful that even if Oilsands Quest can't extract oil from the tar pits, they'll still be able to extract value from the stock. More than 96% of the 999 CAPS members rating the company think that value will bubble up to the top. Add your opinion on the Oilsands Quest CAPS page today.

Don't bring me down
And it was just last week that we looked at the fall of Arena Pharmaceuticals as the Food and Drug Administration released a briefing document expressing doubts about safety for its anti-obesity drug locaserin. While I thought it might be a typical case of overreaction after Vivus (Nasdaq: VVUS) had its fat therapy Qnexa shot down and lost more than half its market value in the ensuing sell-off, the FDA panel actually came out and recommended not approving locaserin. I'd say that it's not looking too good for Orexigen Therapeutics (Nasdaq: OREX), which is coming up for a hearing next month

Highly rated CAPS All-Star member Momentum21 gambled on its previous fall from grace, but now thinks Arena Pharmaceuticals can bounce up again from the latest plunge.

Gambled in CAPS (lost) and now trying to catch the knife in real life...bought in at 1.99. The premise: there is time left for a bounce down here. Probably should have given myself a bit more cushion however and gotten greedier with the limit order. 

Obviously the time frame is getting pushed out...this is not a bet on a miracle approval, just an overshoot to the South. Time will tell!

Can Arena recover from the liposuction the market just performed on its stock price? After all, Vivus' just-reported Qnexa showed new, positive clinical results. Let us know in the comments section below or on the Arena Pharmaceuticals CAPS page if you think there can be fat profits made here.

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 at what has happened to your stock can give you an edge over other investors who just react to the market's lead.

That's why it pays to start your own research on these stocks on Motley Fool CAPS, where you can read a company's financial reports, scrutinize key data and charts, and examine the comments your fellow investors have made, all from the stock's CAPS page. Then you can decide for yourself whether it's ready to come back from the dead.

First Solar is a Motley Fool Rule Breakers selection. Try any of our Foolish newsletter services free for 30 days.

True to its name, The Motley Fool is made up of a motley assortment of writers and analysts, each with a unique perspective; sometimes we agree, sometimes we disagree, but we all believe in the power of learning from each other through our Foolish community. The Motley Fool has a disclosure policy.

Fool contributor Rich Duprey does not have a financial position in any of the stocks mentioned in this article. You can see his holdings here.