Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of cancer-busting biotech Onyx Pharmaceuticals (Nasdaq: ONXX) got a clean bill of health today, racing to gains as high as 17.9% on very heavy trading.

So what: In the early morning hours, Onyx partner Bayer HealthCare Pharmaceuticals announced phase 3 trial results for colorectal treatment regorafenib. The study showed a statistically significant increase in survival rates when compared with placebo, and Bayer hopes to market the Onyx-developed drug worldwide under a royalty agreement.

Now what: Anything that puts a dent in cancer deaths is likely to become a serious blockbuster, inviting both speculators and well-informed investors to make big bucks. Onyx is actually pretty unlike anyone else in its field by not sporting a volatility-tracking beta value in nosebleed territory. Investing in fellow cancer-drug specialists Oncolytics Biotech (Nasdaq: ONCY) and Dendreon (Nasdaq: DNDN) is not recommended without a large supply of antacids and aspirin on hand -- though the gains can be astounding if the respective drugs work out as planned and you have the stomach for one heck of a roller-coaster ride.

Interested in more info about Onyx Pharmaceuticals? Add it to My Watchlist.