I dont know the details of this but there is an arrangement...

I dont know the details of this but there is an arrangement whereby traders can trade a share up to (I think) 20 times per day for 1 lot of brokerage...

Used to be through a firm from perth that was taken over by Comsec last year... but the deal is apparently still available through comsec.

There is a small group of share traders/ investors who get together informally every couple of months in Bendigo and at one of the meetings last year two blokes attended who do this sort of thing for a living.(Thats when I became aware of it.)
Both had multiple screens (6 from memory ) and would buy and sell purely on momentum.
They were not automated, used to watch the screen and buy and sell manually....whatever was moving.
I am fairly sure they didnt short sell though...... or at least they wern't back then.

My point:

They are individuals, not big corporations, so the very low brokerage arrangement for multiple trades IS available to the likes of the smaller player.

Cheers,

Bendigo