There's a bid at $6 with a min fill size of 1k and the last price jumped to way below it without hitting it. How is that possible, other than someone trying to paint the tape by trading with himself on one exchange way below the NBBO? Same thing happened yesterday too. I had a SMART routed bid for 25k+ face value, no min fill size, and the Last price jumped from way above my bid to way below my bid without hitting my bid. I suspect either manipulation or extreme stupidity on the part of a seller.