If most cwir longs are buying on margin that may be a large part of the reason why these shorts able to manipulate the cwir pps. This would mean that longs and shorts are borrowing to fight each other within the pps. Since it's always been easier to scare a penny investor than recruit them, the shorts are able to keep the pps down. Bottom line being if you're buying on margin don't be surprised if shorty is able to cost you a ton of cash.