>>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.
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1
