Each solidly to their own, examples change all the time ...i try to use at least enough cash that I may exit after one tick up on that particular stock with enough left over after trade costs and tax paid to buy some take away lunch...happens more regularly than I prefer.
I also in certain circumstance I will trade squarely with 1k for every cent of the share price....so I quickly get outclassed on stock more expensive......smaller amounts (amounts can be increased as confidence in trend increases intraday) can be easier to exit with and might make all the difference at times....also helps with filling out the forms...the faster here the better these days.
Heaps more and everyone will have theirs...so many factors.
