My guess is that the seller has dried up, it's mostly been coming from Bailieu and EUROZ and then Comsec and Etrade.
So to sum it up retail has panicked from seeing little shown on the bid and the instos (could be clients orcould prop desks) are buying in a sniper fashion (i.e. not showing their hand).
The main Insto brokers buying have been Deutsche and Goldmans (gobbling up almost 3 million shares since the 2nd of October (minus the last 3 days - as it is still anonymous). That almost half the total buying of 6.2m since the 2nd October (that is up to date as it includes anonymous period - just can't tell who it is).
Keep going up you little beauty !
IRN Price at posting:
76.5¢ Sentiment: LT Buy Disclosure: Held