The lot sizes we used to complete the challenge:
1) During the first week we started by using 0.02 - 0.04 lot size per week … We made sure that we start slow on the first week
2) during the 2nd week we increased by 0.02 lots per each trade!
3) during the 3rd week we would start by using 0.40 lots per each trade which increased our profits fast
4) during the 4th week we used 0.50 lots per each trade after we built up our account.
We try to use 2% - 4% risk per each trade we take to help us not loose to much of our account per each trade.