I do think you guys are discounting the effect of margin rules change on stocks, forced selling for awhile now.
IB Risk Management department has submitted a revised schedule for the Small Cap stock margin increase (note that this includes any stock having a market cap below USD 250 million, or equivalent). COB= close of business COB 9/21 goes to 35% COB 9/23 goes to 50% COB 9/28 goes to 75% COB 9/30 goes to 100%
If ZBB has been used as margin collateral and then lost half it's value through forced selling before they revised the dates, and rattled some more holders on the way down...then deleveraging your position would make you choose the loser to sell wouldn't it? compounding the selling pressure... some would sell this before, oh say, a company with a green income statement :)