Biotech stocks haven’t performed very well over the past 12 months. A couple of them have seen downright dismal results. Shareholders of Celldex Therapeutics, Inc. (NASDAQ: CLDX) have watched the stock tank over 80% in the last year. Ionis Pharmaceuticals, Inc. (NASDAQ: IONS) doesn’t look much better, with a drop of nearly 70% during the same period.