They (clearing houses) raised margin requirements, specifically on AAPL. This creates forced selloff in AAPL and other speculative stocks that have decently appreciated YTD to satisfy new margin requirements. AMRN may be affected somewhat because, despite recent drop, it's still almost doubled compared to price of $6.50 earlier in Jan'12.
This actually creates good buying opportunities in equities... but need to be patient to catch a good price to go long.
I expect at least a 10% bump up from the current price ($12.25) and the OB publication on 12/14. What happens at that point depends on what is published. I think Rosenman is right that ods strongly favor inclusion, but figure there's at least a ten percent chance of rejection or further delay.
Close on the heels of that action should be a reasons for allowance letter, followed by a NOA a couple weeks further down the road. I bought a bit more today to simply trade into the 14th. Will keep some powder dry on the 14th for any opportunities for cheap shares that arise.