My research work will focus on the informational role of price processes and trade volume. The result should provide a better understanding of fluctuations in prices, and contribute to the desirability and feasibility of policy measures which reduce asset price and exchange rate volatility. My theoretical model will show, how traders can infer more precisely information from the price process than from the current price. If traders consider the whole price process, prices adjust more quickly to the "full information price", making them "more efficient". The difference in the speed of adjustment can be measured with an Entropy measure. As prices adjust faster, the expected volatility of prices changes and can be price path dependent. Pricing of options has to take these effects into account. So far, past volatility has been used as a proxy for future expected volatility. This can lead to mispricing not only of the option but also of its underlying value. For example, after the German Bundesbank intervened in the Dollar-DM exchange rate last spring, the Dollar jumped by 6 Pfennige, which caused a huge price increase in both put and call options and led to some confusion. My model will also explain the impact of the revelation of former private information. This is especially important for government institutions, enabling them to determine the right time and nature to release public information.