whatever their plan is, they are in no hurry to get their order...

whatever their plan is, they are in no hurry to get their order filled.

With that size at that price the only way I think they would likely get fully traded is with news flow - this would probably need to be negative too, in order to spur some sizeable selling.

You then ask the question, why leave a bid there that is only likely to be completely filled on negative news? It's looking less and less like a legitmate position in my view.