You probably don't need any more proof that the market's been volatile recently than simply looking at the wild swings your portfolio has taken. Mine shows that some blue chips are up, some small caps are down, and growth stocks are all over the place.

The S&P 500 is currently at the highest it's been so far this year, but 22 of its constituent companies are trading at their lowest price-to-earnings multiples in five years. These include well-known firms such as Texas Instruments (NYSE:TXN), Google (NASDAQ:GOOG), Dollar General (NYSE:DG), Rowan Companies (NYSE:RDC), and Nabors Industries (NYSE:NBR).

Growth alert
It's well documented that many value investors have been getting excited about a large-cap sale, but it's not just blue chips that value investors should be hunting for. Growth stocks, too, have been pummeled over the past couple of months. You remember growth stocks, right? They're the small, high-on-potential firms such as Align Technology (NASDAQ:ALGN) and TurboChefTechnologies (NASDAQ:OVEN) that have helped the Russell 2000 index return more than 15% per year over the past three years.

Now, while the Russell 2000 has been great, the team at Motley Fool Rule Breakers is even more excited about some of the growth stocks the newsletter focuses on. And given the market's recent volatility, a few of them are now available for 50% off. And that's in spite of the fact that when it comes to their business potential, very little has changed.

Find the best with the most
One of the Russell 2000's holdings is Rule Breakers-recommended EncysivePharmaceuticals. The company makes a new drug called Thelin, which has vast potential in the pulmonary arterial hypertension market. Although there are other drugs that treat this, Thelin has the ability to gain huge market share due to its dosing advantages, safety, and efficacy in treating the disease.

The potential for Encysive to be the best in its class in the world of pharmaceuticals is what led Charly Travers to recommend the stock to Rule Breakers members. As Charly said, "Encysive didn't invent the mousetrap, it built a better one."

That's Encysive's huge potential -- and it remains unchanged. The market, however, has reacted to news of a delay in the launch. Apparently, the FDA still sees a remaining issue. Although that delay could cause a few problems if Encysive is required to conduct new clinical trials, Encysive has received authorization to sell Thelin in all 25 countries of the European Union -- what Charly has called a "big value-driving event."

The uncertainty surrounding Thelin has caused Encysive to trade 51% below where it was in March. And yes, there are risks. But are you willing to pass on that much potential at 51% off? If you say yes, I'll gladly take those shares (and in fact, I already have).

A breaking opportunity
Encysive's not the only Rule Breakers recommendation that's seen its price slashed in recent months, even as the growth stories remain intact. If you'd like to see what other great growth companies Fool co-founder David Gardner and his team are recommending, consider a free trial of Rule Breakers. You'll have access to all of the picks and research without any obligation to subscribe.

Sales aren't just for large caps. You can also get great growth potential for a low, low price. Just click on this link to see.

This article was originally published on July 31, 2006. It has been updated.

Fool sector head Shruti Basavaraj owns shares of Encysive. The Fool's disclosure policy isn't for sale ... it's free.