Sell-off might be more to do with current debate about future of lithium batteries. Some good reading here:
http://www.reuters.com/article/2013/04/11/us-usa-batteries-technology-idUSBRE93A0SQ20130411
http://www.reuters.com/article/2013/04/10/us-boeing-battery-lithium-ion-idUSBRE93904420130410