This dissertation contains four studies on different market structures and their impact on market quality. Article I studies the effect of introducing stock index futures contracts on the underlying stocks. The results indicate a lower liquidity level in the underlying stocks. However, after introducing market makers to the futures market, liquidity improves in the underlying stocks while trading activity and volatility remain unchanged. Article II investigates price discovery in the gold futures markets in China and the US. The gold supply and demand from China have been among the world’s largest in recent years. The results show that the gold futures markets in China and the US are cointegrated. Despite its short history, the Chinese gold...