The past week oil has made a drop of over 10%. Corn dropped 5% the past two days and so did ethanol.
So I think that the first major drop of PEIX was caused by oil. This also made a lot of other stocks drop. The drop of the Ethanol price made the ethanol stocks drop even more. Now today oil is also dropping again, making the other stocks join the drop again.
Oil supplies did decline a bit, which probably made oil drop less after the release Wednesday. Ethanol however did increase with 4,7% this combined with the lower corn price seems to be causing drop of ethanol.