If the strategy only involves selling than 0.5% is enough but if it's a buying may be 1.5 to 2% slippage is required
@arumugampk if you mean return on capital deployed then it depends on the base capital you are trading with on a higher base even 20-25% annual return in good but on a smaller capital you may not get that kick in a 20% return.
I also think higher expectancy is needed to psychologically stay with the algo also it helps to come out of DD phase faster