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)

Thursday's Change

Cisco (Nasdaq: CSCO)

***

(16.2%)

RINO International (Nasdaq: RINO)

**

(15.8%)

ZAGG (Nasdaq: ZAGG)

**

(13.6%)

From peak to trough, the market swung 175 points, though it ended the day down only 74, or a little more than a half-percent. The day could have been a lot worse, but stocks that went down significantly more are still big deals.

The devil's in the details
It's no secret by now that the weight of the market's collapse yesterday rested on the shoulders of Cisco, which blew its earnings by a wide margin. That's "blew" as in beat. Analysts had been expecting a healthy $0.40 per share in the third quarter, but Cisco apparently sucked the air out of the room by coming in at just $0.34, though on an adjusted basis they beat expectations. The 16% plunge by the stock was the biggest drop it has experienced since 1994!

The market obviously sees Cisco as a bellwether stock and there's some sense to this: its earnings come out a month later than many other tech companies -- Hewlett-Packard (NYSE: HPQ), Intel (NYSE: INTC), and Apple (Nasdaq: AAPL) all reported last month -- so it has an additional month of insight into what's happening in the market. What really got them was apparently the revenue guidance of only 3% to 5% -- half the growth that analysts were looking for.

Yet too much was read into this report. A good portion of the miss was at least partly caused by reduced government demand, and Intel recently raised their margin guidance for the coming quarter. Obviously not everyone is expecting it all to be doom and gloom.

Not surprisingly, many CAPS members like MalcoweeDaddy took the opportunity of the depressed price to buy in.

Impeccable balance sheet with a huge cash hoard. It dropped precipitously today to almost a 52 week low on some negative comments about future earnings by the CEO. I saw the opportunity to get a good company at a good price so I pulled the trigger.

The sky's not the limit
RINO International investors got gored yesterday by a report from a short seller who called the Chinese water treatment specialist a fraud. It alleges the company is lying about its revenues, lying about its relationships, and lying about work that it's done. The firm Muddy Waters recently shredded Orient Paper with a similar charge.

If true, there were a lot of smart investors who got snookered by this. Not saying it can't happen, but the folks at Dremen Value Management and Vanguard are pretty sharp when it comes to investing. CAPS member sebastoro also offers some sage insight into the "organized short attack" situation.

So finally, this kinds of attacks has [been] common in Chinese small caps, look at (Universal Travel) and ONP recently attacked and both regain their prices before the attack, both were real companies and now the shorts are losing big money there. Rino its the same a very [interesting] company, at a very good price and in my opinion this attack is just a big buying opportunity that im going to take advantage and i hope that the market does that too.

Only you can decide whether RINO International is right for you. Add it to your My Watchlist page where all the Foolish news and analysis about this stock is aggregated for you.

A giant leap...down
iPhone cover maker ZAGG had a big run recently and its quarterly earnings beat analyst expectations by a healthy margin, so it's surprising to see them have traded down so far. But another article questioning the propriety of a company may have had a hand in it, though today the stock is up today as of this writing.

In addition to its iPhone case, ZAGG has partnerships with AT&T (NYSE: T) and Staples, and continues to sell its products through Best Buy and other electronics retailers. The introduction of the iPhone 4 and the HTC Evo helped drive sales 138% higher year over year as well as 53% sequentially.

TMFRazorback likes the strong record it is cobbling together, but tell us on the ZAGG CAPS page whether you think it can still dial up higher sales.

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's 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.

Best Buy and Intel are Motley Fool Inside Value recommendations. Apple, Best Buy, and Staples are Motley Fool Stock Advisor picks. The Fool has written calls (bull call spread) on Cisco Systems. The Fool owns shares of and has bought calls on Intel. Motley Fool Options has recommended buying calls on Best Buy and on Intel. The Fool owns shares of Apple and Best Buy. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors.

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