I'm new and using trial version, why is green up and down?

[midge]

Hello, ive just started using the trial version which has just the one click screen with no adjustments allowed, ive found all i can do is click back or lay, nothing is automatic (in the youtube video the guy clicks lay then if it can match it does and if not it cancels it) anyway, no problems with that (unless ive got it wrong) as i know you have to pay for the proper version.

Ive been doing the scalping, essintaily ive just been laying at say 3.4 and then waiting for the other side to pick up to 3.5 and backing, once ive successfully done this ive noticed the number circled below goes up and down, indicating more or less profit,and i dont understand why? surely if the profit is banked it wont go up or down?

[Euler]

Only when you click that column will the profit, or loss, be banked. If you look at the column to the left of it you will see that you have backed one runner and not closed your position. All the time the position is open the odds are moving and affecting your potential profit. Click on the trade profit column to grab your profit. Tick the green check box to ensure the profit is spread across the field when you take the profit.