Whether a stock moves fast or slow, one thing is always true. The forces of supply and demand determine the price of Proshares Ultrashort Oil & Gas (NYSE: DUG) and every other stock on the market. The price someone is willing to pay for DUG directly impacts its price, but that is offset by what others are willing to sell it for too. The good news is, we can see where these decisions are being made more aggressively, and we can use that information to our advantage. This is what we have done in the example below. Our data was current at the time of publication, but it is not updated in real time here. If you want real time updates, or data on a different stock, please get one here Unlimited Real Time Reports .