Actually, that is very common with the biotech stocks. Since most of these start-up companies deal with multiple drugs in their pipeline, any not-so-good news may crush the stock. However, good news on any of the drugs may lead to the recovery within a short time. The mood swings once in a while leading to catastophe, but generally it recovers after a while. XOMA, ENMD, INSM, ANTH, . .....all these stocks took beatings. KERX is a recent example. I think Affy and Ziop will recover with some good news with some of their other drugs in the pipiline. ZIOP has Indibulin (Zeo 301) which is undergoing phase 1/2 trials for breast and ovarian cancers, and in my opinion Indibulin is much better than palifosphamide.