One thing to remember, if the Government can prove you are trading for yourself as a regular job then they could turn around and treat profit on trades as income and of course allow all losses as well.  Not often done but if your sole business is as a day trader moving in and out it's something they could nail you with.

For most of us it's just a pain at end of year doing all the paperwork to see what the capital gain OR loss was.

For lots of fun start throwing in flow thru shares and partnership fund investments etc. etc.