Quote from Andreas_Lueti:
I do agree in a lot of your points but a systemtrader with 100% rules will not have any problems switching from 10K to 1 million.
If you trade a little bit longer term 1 - 10 days slippage would not that great problem.
Very correct. if you have a well defined quantitaive system with risk rules and position size rules, the 'system does not and should not care whether you trade 1 million shares or a 1 lot. Of course this assumes that your system has made allowances for slippage and market capacity/liquidity.
Psychology is only a factor for discretionary traders or for pseudo-systematic traders (systematic traders who constantly second-guess the system).