BOSTON ( TheStreet) -- Nothing blows up like a biotech or drug stock. When things go wrong -- a failed clinical trial, an FDA rejection -- investors bail and stocks implode. It's the dark underbelly of a high-risk, high-return sector. Here are the five worst-performing drug stocks this year. No. 5: Vermillion What goes up, must come down. That's certainly true for Vermillion ( VRML) and its stock price, which rocketed 30-fold following FDA approval of an ovarian cancer diagnostic test in Fall 2009. Selling the ovarian cancer test in 2010, however, has proven significantly more challenging, which is why Vermillion's stock is now firmly back on earth. The stock: Vermillion shares are down 83% this year as sales of the OVA1 test continue to disappoint.