There is still this system that banks delay transfers for three...

There is still this system that banks delay transfers for three days.
If I transfer, electronically, from my CBA savings account to my shares account -- it takes three days!

I had a teller tell me one day that the three days is required in case I change my mind, they are just protecting me from myself?

If you consider how much money you could make by holding all the money for three days, it would be mind boggling