Probably buying for their hedge funds to pick up the relatively risk free 2c margin
If there was a higher bid coming the market would probably have sniffed it and be trading at a premium to the 70c GEM bid
UBS could be accumulating a nice stake that they could nogotiate with in the event of a new buyer coming in - any new buyer would need a large line of stock
At this stage doesnt appear that a higer bid is imminent