Why stop? The only time you need to stop is if you have no advantage.

There is nothing to suggest that because you have had a good run, that it will suddenly turn bad... Same goes for the opposite.

There was a similar thread a couple of months ago, and people were basically split on the idea.

My question is what is the limit? If you are $500 at some stage of the day, why stop? What is the difference between betting on the next race and waiting 3 weeks to have your next bet?
At some stage if you are going to have another bet, you will be risking some of that money.

I bet to a system, and as long as the bank continues to spiral upwards, I could care less about the end of days profits...

If you have faith in your selections and strategy and believe in its long term success, then I believe there is no argument to suggest that you will be financially better off stopping.

Sure sometimes, you might have had enough for the day. You figure you are up, so yeah turn off the radio, turn away and go and do something else.
But at the same time, I would suggest to do the same regardless of your position at any time of the day. If you need a break, have one.

Just remember, it is the long term success of your punting that matters, not day to day.