BitMEX Army assembles

leverage doesn't matter that much if you set stop losses everytime, unless you go 50x-100x.
position size is more important.
if your position size is too big and you go on a losing streak where you get stopped out everytime you will lose too much money and it will be hard to make it back.
never use more than 3x your entire account as position size.
for example if you have $1000 worth of BTC, your position should be 3000 MAX.