No. 3: Marina Biotech (MRNA)
It's bad enough that Marina focuses its R&D efforts on RNAi drugs, an unproven field that has been largely abandoned by everyone else. Worse, Marina's drugs are still in the preclinical and early, early stages of clinical testing. What Marina did well in 2011 was raise money but even with that accomplished, the company's balance sheet is still cash-poor.The stock: Say "RNAi" to an investor, and he'll either laugh or run away screaming. Marina shares have lost 92% of their value this year.