Note that these are PT shares on Bitfunder that are being sold OTC by the owner of the shares for close to their current value on Bitfunder. At a guess he's doing this because the exchange can't support the sale. The upshot is that you may as well buy now on Bitfunder if you can since there is minimal price advantage to buying them OTC (and that there'll be another dividend payment soon). Prices are somewhat higher on btct.co but as you can see there's no way to transfer the shares to this exchange to take advantage of the difference.