Merck (NYSE:MRK) stock soared almost 3% Wednesday to close in on a new 52-week high after the pharmaceutical giant announced the FDA accepted its new drug application for a pill form of its antifungal drug Noxafil.

Merck currently sells the drug in liquid form, but the pill formulation gives a new option for patients getting treatment in a hospital setting. The therapy is for those who have severely compromised immune systems, which puts them at great risk of infection from Aspergillus and Candida, two invasive fungal infections. In addition to FDA approval, Merck is seeking approval from European regulators and hopes to eventually get the pill formulation approved worldwide.

Dow pharmaceuticals stocks actually had a big day on Wednesday as Pfizer also powered higher on news the FDA designated its experimental breast cancer therapy palbociclib a breakthrough drug, which will accelerate the development and review process.

Superball bounce
A lot of familiar names were also active on Wednesday, stocks that for the most part have been beaten down over the past few weeks or months, but are bouncing around to extremes. Emblematic of that manic behavior is VirnetX Holdings (NYSEMKT:VHC), which jumped 10% after announcing on Tuesday that Europe's patent office intends to grant it a patent for third-party VPN certification.

VirnetX has been all over the place recently after a mixed court decision involving an infringement case with Cisco (NASDAQ:CSCO). While the patents of VirnetX were found to be valid, it was decided Cisco didn't violate them. Because Apple had just lost a case to VirnetX over the same issues, investors worried they'd now come back and appeal.

Having lost a quarter of its value following the Cisco decision, its stock has gained more than 20% over the past week from bolt-on "victories" like those with the European Patent Office and having added additional specifications to existing patents. It's hoped these kinds of small wins will allow it to continue to triumph in the courtroom while protecting its backside from any new challenges.

Star Scientific (NASDAQ:RCPI) is another one that's bouncing around, though more often than not it seems to fall harder than rise meteorically. Wednesday, though, was one of the good days, jumping 14% on no discernable news. It's still under investigation for stock transactions it made, but after a forceful attack against the trial attorneys piling into the stock and Wednesday's comeback, Star's stock is now 16% higher than where it was a week ago.

Don't bank on it
One of the biggest gainers on the day Wednesday was National Bank of Greece (NYSE:NBG), which seems to be surviving on little more than sheer will -- and the big backing of its government. Its attempt to acquire Eurobank fell apart over the weekend following the European Union, European Central Bank, and International Monetary Fund suddenly questioning the validity of allowing an ailing bank to grow larger than home country's entire GDP. They worried that if it failed it would require a huge bailout they could ill afford, after which National said private capital suddenly dried up.

But on Wednesday its stock soared 19% after it said it would raise 1.9 billion euros via a convertible bond offering and 9.75 billion euros via a rights offering. While the government is propping up the country's biggest banks by providing them with most of the money necessary to recapitalize, they're still required to find private investors to contribute at least 10% of its new common equity. National Bank of Greece says it will be hard-pressed to achieve that level, so I don't see much reason for investor euphoria at the moment.

Whoa, Nelly!
While trading in these volatile stocks can be exciting at times, and the thought of making a killing on moves of just a few pennies seems like a path to riches, you're more likely to see wealth destruction following that road. In these troubled times it might be better to stick with larger, more stolid plays like Merck and Pfizer than chasing the dreams these other troubled names provide.

Fool contributor Rich Duprey owns shares of Apple, Cisco Systems, and Pfizer. The Motley Fool recommends Apple and Cisco Systems. The Motley Fool owns shares of Apple. 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. The Motley Fool has a disclosure policy.