PEIX, GPRE-- one thing to consider here is that GPRE reports results in the a.m. and PEIX reports them afterhours. Some like Chen were thinking that GPRE may have a lousy quarter because of the nat gas price spike, which would eat terribly into their already thin profit margin.
So if GPRE reports lousy news that a.m., it could cause the small ethanol sector of stocks including PEIX and maybe REX to drop.
PEIX could recover the following day if their (PEIX's) earnings report is great, but there may be selling pressure on Wed if GPRE reports sour news early in the day.