>>>To raise tax money that is a rounding error in the federal budget?
>>>It is simply not a significant source of revenue.
>
>Meanwhile there are "traders" who set up shop on/close to the same routers as trading exchanges so their trading algorithms get a split second extra time before positions become evident to the wider market. That time is used to take positions and effectively levy a tax on transactions, in exchange for nothing. If additional tax is needed, start with these parasites.

All documented in "Flash Boys" by Michael Lewis. It's been a huge bestseller over here. Lewis has a knack for writing nonfiction books that read like novels.