One has to also think about statistical probability having the trend continue after a move of 50 points has already been done from the bottom.I would put getting 30-40 points more as a low probability unless we are in a strong trend day.So if one is entering after 40-50 points,he has to be alert and book profits of 20 points as the day's range comes to an end. Just see how many days we have 80 points and above range from top to bottom.
ATR will be helpful here.
ST