This dissertation studies how the existence of transitory investors, i.e. investors who are only rarely present in the market, affects the market dynamics. With limited market participation order imbalance leads to a price impact and the following reversal on the stock price. Market makers and other immediacy suppliers synchronize the short-term supply and demand by increasing or decreasing their inventories, but they do this only if they can earn returns from providing immediacy. Their counterparties, immediacy demanders, suffer from costs of immediacy when they want to execute their trades immediately instead of waiting for arrival of other investors willing to trade. The first essay presents a structural model of the stock market with ...