WZE at or above $4.68 CO at or above $3.22 UTG (rights) at or below $0.0497 EJ at or below $3.36 ARC at or above $5.71 KWK at or above $5.91 probably some firm had their orders queued up this morning to be vwaped or some other algo and accidentally went market. my guess..
It was Knight, apparently -- see also this thread (not to mention any newsfeed for KCG): http://www.elitetrader.com/vb/showthread.php?threadid=246877