Securities exchanges are becoming increasingly automated. Over the course of the past years, most major exchanges have upgraded their trading infrastructure to accommodate the increase in algorithmic trading. E.g. about half of all trades executed on XETRA, the fully electronic cash market system operated by Deutsche Börse, are generated by algorithmic trading engines. The effects of IS (in terms of infrastructure or in terms of automated trading on the market outcome as well as on the development of the financial markets in general) are so far not well understood. In this project, using primarily the event study methodology, IT-driven events will be analyzed with respect to their different impacts on financial markets. At the same time, we address and explore the methodological challenges associated with applying the event-study methodology to financial market data.