Are you trying to make money? Or do you have money to invest?...

Are you trying to make money? Or do you have money to invest? Making money short term on the sharemarket means you are a trader and you need a set of rules to trade by to limit losses (and there will be losses) and maximise gains. Investing means parking your money for a longer timeframe and aiming to make a gain. No risk, put it in the bank and earn interest.

I do hope you have already applied a stoploss and are out of the market as Monday is going to be nasty.

Another form of investment is in yourself. This you are already doing, so think of your housebuilding as an investment and the long term gains you will make when you sell it. We owner built our current home 15 years ago, then sold the house we had been living in.

You are building a whole new skill set. I don't know what the current rules are, but you could have a new owner builder license every 5 years, so build a new home every five years, live in it and then sell it. Check out with an accountant or someone similarly qualified what the rules are and make your money! Family home attracts no CGT when sold, plus you also gain on your own free labour.