This probably isn't an IB-specific question but since I'm using them, here goes: In the out-of-hours session (now, and for most of the past few hours), for the Feb 107.0 Puts traded on the ECBOT, there are 1300 contracts bid at a price of 0. Ask is at 2/64. What is going on here? Are locals or market makers allowed to bid at a price lower than one tick?? What is that level? Thanks ...