Clarification goes like this.
If you make a profit,the profit goes onto your score.
If you lose,you subtract the loss from your score.
You cannot have a minus score.If somehow your calculations come up with a minus,you restart with a bank of zero.
Sort of a Robin Hood approach.Steal from the rich to support the needy.

Current balance at $1,053

gone so far: win/loss/win/loss/win
so i'm due for a loss next week.

cheers