Studies on stock market efficiency

This dissertation consists of three empirical studies on capital market efficiency in a broader sense. Two of the three papers are dedicated to the examination of short-term stock-returns in the wake of large one-day price changes – positive or negative. If significant abnormal returns can be found after large price changes this may indicate improper information efficiency. One if not the only way for listed companies do disseminate information is via investor relations. The release of ad-hoc statements levels the informational playing field for all investors and should thereby help to prevent overreaction or return drift. The third paper deals on the one hand with the causality chain of investor relations and liquidity and on the other hand with the question if insider trading and investor relations are positively correlated.