If you want to really gamble your earnings, go to the ato and search for ITW Variation, which is an Income Tax Witholding Variation.
With this you can estimate your loss on other investments as a forecast of your taxable income. The ATO then (upon assessment) send a letter to your employer to take the equivalent (less) tax out, since you will be claiming it back at the end of the year.
It's based on an honest system and if at the end of the year you do a tax return that proves your estimate was wrong, you will have to pay the difference back and if you were way out (paid too little tax), they may not allow you to do this again if applied for later on.
It's a great way to maximise your available capital but risky if you get the estimate wrong.
