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 biotechnology company Sunesis Pharmaceuticals, Inc. (NASDAQ:SNSS) sank as low as 12% today after an ethics committee recommended that a key study assessing the use of its vosaroxin treatment for acute mylogenous leukemia be discontinued.

So what: The Data Monitoring and Ethics Committee recommended that the monotherapy vosaroxin study sponsored by Cardiff University be dropped early "as it did not meet the pre-specified criteria for advancement," raising a bit of concern among analysts over the drug's sales prospects. After the initial opening plunge, however, the stock trended up steadily throughout the day and closed Tuesday down just 4%, suggesting that Wall Street still has some belief in vosaroxin's broader potential.

Now what: Sunesis will continue to work with Cardiff University to understand why their outcomes differed from its own phase 2 REVEAL-1 trial. "We are confident in vosaroxin's broader potential, which we continue to explore through investigator-sponsored studies, such as the newly initiated MD Anderson Cancer Center trial in previously untreated AML and MDS," said CEO Daniel Swisher in a statement. So while the stock is certainly too speculative for average Fools, biotech traders might want to look into this small setback as a possible buy-in opportunity