when I was studying for the ISE market maker exam (circa summer 2002) two rules really stuck out to me: Trade or fade (which meant market markers had to clear up inter exchange locked quotes) Customers who automated their trading (were treated as professional Andover their priority). The former rule was placed because of your antics and other people’s and made the profit a market maker’s. the latter was to prevent customers from becoming defacto market makers without paying the seat fees. edit: I think trade or fade was like 30 seconds. ETJ might remember.