Nowhere is the free market system exemplified by supply and demand than the stock market. To the day trader, position and timing, rational strategies, and disciplined decisions are everything. What if you knew ahead of time the chances a share's market price would go up or down and by how much? How would being informed of an impending price drop or rise along with the new market price support your decisions? Think of how useful this tool could be to a day trader. I know, I'm a day trader.