Drug development is a losing game full of highly trained professionals who would rather be lucky than talented at their jobs. This is because experimental new drugs fail so frequently that an entire career without one successful new drug discovery under their belts isn't uncommon.
Doing everything right doesn't guarantee success in this business, but there are signs of trouble that can make the long odds much longer. These two biotech stocks have been flashing signals that should make any investor too nervous to pull the trigger.
Data source: Yahoo! Finance and company filings.