There is a pretty good chance that this person's post was single-handedly responsible for the 15% increase that just happened (and that began at roughly the same time as this person's post here). A single unsubstantiated comment by some anonymous person on a forum.
Oh, and I don't think withdrawals are working. I just tested it and no. And I haven't read any other claims (then again, if some other anonymous forum members now start to say the same thing the price will jump again)