The opening days trading of Facebook shares shows that of the 43m traded at $38 they almost all happened at the bid. The investment banks behind the IPO are permitted to undertake ‘stabilisation’ with the stock they have. This prop trading by them may or may not make them money – but clearly they don’t want the price falling below $38. It will as pressure mounts, not least from hedge funds, who will see an opportunity to rape and pillage Facebook’s shareprice.