Ask Colin

Professionals stay out of the opening of the market, unless they think the amateurs have it way wrong, in which case they will be on the other side of the trades, "fading" the public view. Such clear situations do not happen all the time, so mostly they stay out. Most amateurs act early in the day and leave the rest of the day to the professionals. Hence, it is the professionals who trade the market to some sort of consensus of value and close it there.