Weak-Form Market Efficiency of the Nigerian Stock Market in the Context of Financial Reforms and Global Financial Crises

The weak-form efficient market hypothesis for the Nigerian Stock Market (NSM) is explored using different statistical tests. The analyses use overall stock market returns collected over the period 2000–2010. It is shown that the NSM is not weak-form efficient which questions the benefits of the 2004 financial reforms. It is also shown that the degree of market inefficiency varies across the periods corresponding to the financial reforms and 2007 global financial crisis, for daily and monthly returns. The results are important to security analysts, investors, and security exchange regulatory agencies in their investment, stock market development, and policy-making decisions.