Unless they're announcing that Overstock will be sold on the Ravencoin blockchain to anonymous investors, I don't think this price will hold very much longer.
I thought that they could use RVN on tZero like coin for doing IEO-s.
I'm sure they will. This was the assumption that got RVN it's 300 satoshi value. Maintaining the recent highs would have needed an announcement along the lines of, 'We are going to list Overstock shares for sale on tZero using Ravencoin's blockchain and will be paying out future dividends in RVN'. I do not believe this will happen anytime soon, so it's buckle up your seatbelts and hope that the price holds in the 600 satoshi range once this correction comes to fruition.