leeb : my system always OP buy and sell at the same time only in the start time. After that it will forward separately. When sell or buy hit TP it will restart to level 1 and the others still continue opening until it TP.

As my experience it never higher then level 8... u can backtest my system...

it happen once when "katrina" the price gone with the wind.. until 300 pips.. but in the next day it TP.. because it retrace. That's why i choose 0,1 lot as example..because it still in our money management. But it still profit enough. If you have a huge balance you can put higher lot.