You saw the headlines. You know your stock made a big move one way or the other over the past week, but what does that portend for its future? If there's not a fundamental basis for a stock's run higher, or its trip to the cellar was fueled by transient, panic-driven selling, those gains and losses might not hold -- and therein lies the potential for investors to profit!

Here we look at one stock that stumbled and one that soared. By pairing the latest news with the collective wisdom of our 180,000-strong Motley Fool CAPS investing community, we might be able to discover whether your stock's latest exploits are a short-term hiccup -- or the start of a much bigger trend.

72 inches down
Normally you wouldn't expect a stock that's made it through the regulatory agency's labyrinth to get beaten up the way that Horizon Pharma (Nasdaq: HZNP) has, but there were apparently some well-founded fears that because of its size it wouldn't have the financial wherewithal to launch its new rheumatoid arthritis drug Rayos without a big, dilutive offering. Now the drug developer announced just such a secondary, and the stock is getting slapped around once more.

Horizon's other drug on the market, Duexis, was partnered earlier this summer with Mallinckrodt, a division of Covidien, to market the drug in U.S. while the drug developer inked a similar deal with Grunenthal to do the same in Latin America.

There was a big run up in Horizon's stock prior to approval of Rayos, perhaps with the hope that Covidien or some other pharma would sign on to market the new formulation. But following its approval, the stock quickly lost a quarter of its valuation on the financial worries, as well as the fact that it really will serve on a niche market and didn't have blockbuster potential.

How well the drug sells remains to be seen, but Horizon lost yet another quarter of its value after pricing a secondary offering significantly below Thursday's closing price of $4.58. Worse still, Horizon increased the offering size by 40% to 21.4 million shares, a pretty steep dilution in any book. It may have been necessary and more can probably be anticipated, but that doesn't mean the market has to like it.

If Horizon can't build up its sales force enough to push Rayos to sufficient numbers of patients, thus padding top-line results, it may be it won't be able to justify even this discounted level. Tell me in the comments section below whether you think Horizon Pharma will find a partner to fill in the gaps in the field.

No longer living large?
Yet, maybe it can take hope in the performance of Savient Pharmaceuticals (Nasdaq: SVNT), a similarly beaten-down biotech that has since emerged from the valley of shadow to much brighter prospects.

In those dark days, Savient was under assault from creditors who tried to prevent it from restructuring its debt. Tang Capital Partners, which owns some $39 million worth of debt, unsuccessfully accused the biotech of being insolvent and asked a judge to appoint a receiver. Tang wanted the courts to prohibit any financing deal to be enjoined as well as to stop any bonuses from being paid to management. The courts eventually said Tang didn't have standing to bring the suit and Savient hadn't defaulted under its convertible notes.

With that, the stock took a turn for the better. Because its stock was decimated by the turmoil, Savient adopted a shareholder rights plan to prevent someone -- namely Tang -- from scooping up the company at depressed prices. Where once it entertained the thought of having Pfizer (NYSE: PFE) or Bristol-Myers Squibb buy it out, now the focus was growing the business around its primary gout therapy Krystexxa.

After having its CEO poached by Dendreon (Nasdaq: DNDN) earlier this year, Savient has a new leader that will oversee the reorganization of the company, one that entails severe job cuts -- more than a third of its workforce in fact -- in a bid to save $56 million. It's hard to say at the moment whether the moves will be enough. While it has sufficient cash on hand, it's still losing money, and Krystexxa isn't exactly a barnburner. The market has given it the benefit of the doubt so far, however, and its shares have risen 400% from their lows.

I find it hard to recommend such a risky company after a move like that, but it's possible someone like Abbott Labs (NYSE: ABT) or Merck even might find Savient a natural fit since they also sell anti-inflammatory treatments. Let me know in the comments box below if you think Savient Pharmaceuticals future lays in being an independent drug developer or as part of some larger pharma's network.

Stop, look, listen
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