The abolition of capital and exchange controls in the UK in 1979 and the series of reforms and deregulations at the London Stock Exchange in October 1986, collectively termed the ‘Big Bang’, played vital roles in the revitalization of London as an international financial center. Beginning in the 1970’s with the revitalization of international finance, there were several key regulatory changes that impacted the relative competitive positioning of major stock exchanges. The first was the abolition of the historical cartel agreements for fixed trading commissions in the US in 1975. With the abolition of capital and exchange controls in the UK, competition from New York forced the unfixing of trading commissions, the allowance of dual capacity trading operations in financial institutions, the opening of the London Stock Exchange to foreign investors, and the implementation of new trading technologies. In this study, I will evaluate the impact that these deregulations had on the London Stock Exchange (LSE), the New York Stock Exchange (NYSE), and other major equity markets in terms of changes in trading volume. Using historic trading records of major cross-listed companies, I will conduct an event study to infer whether major shifts in trading volume between exchanges occurred as a result of these deregulations. I will also estimate the price elasticity of demand among the stock exchanges using data on commissions in different markets. I anticipate that a shift away from the LSE after 1979 to the lesser-regulated NYSE was due largely to the lifting of exchange controls in the UK. Similarly, I predict that the large-scale deregulations that came with the Big Bang will show to have caused the LSE to reclaim much of this lost trading volume and to grab order flow from neighboring European exchanges.