This thesis takes as its subject the market for Initial Public Offerings (IPOs) of equity securities in the United Kingdom. The principal aim of the study is to try to find an explanation for why investments in IPOs in the UK provide an average excess return to investors. Once levels of excess returns have been identified this study seeks to offer 'stabilisation' as intuitively appealing, theoretically sound and practically evidenced explanation of excess returns in the UK IPO market. This thesis then goes on to look at the UK IPO market in more detail, paying particular attention to the roles played by sponsoring agents involved in the IPO process and what impact they have, if any on differential levels of excess returns between IPOs. The economic efficiency of the IPO market is also addressed at this point. The final piece of research in this thesis examines the subject of management buyout flotations. The aim here is to provide evidence to support the claim forwarded that management buyout flotations produce superior performance to the universe of IPOs as a whole. The data set used for this thesis is made up all flotations undertaken in the United Kingdom in the period from 1989 to 1995.