We will think about that, but the problem is, that you cannot guarantee any stop-losses in stock market. So in reality, stop-loss like this is not of much use, because most black-swan events on stocks take place during weekends or nights and when your stop-loss is executed (next day 9:30 EST), it is usually too late anyway.
So it is nice to set a stop loss to 10% of trade, but in reality your pre-defined level is often not achieved and you exit with significantly higher loss.
I have already experienced in my live trading a situation, where the long stock of the open pair went 40% down and the short one went 20% up, both during the (same) weekend. You cannot really control situations like this - the only way is to diversify properly (this terrible drop caused only 4% DD of our pair portfolio).
So we prefer to wait the loss out and use timed stops, whatever the loss is. You can afford that, if you trade more pairs (at least 8, let's say) at the same time.
Anyway, we are open to suggestions here, because this is really important topic. The point is that no matter what level you set for your stop-loss, it is never guaranteed in stock market.
