Abstract:

Over the years, there has been a great debate on whether or not stock markets are efficient. The debate has always been on the validity of efficient market hypothesis, not until the recent when Lo, (2004) developed the adaptive market hypothesis stressing that market efficiency evolve over time. This new assertion has been subjected to critical debate. The current study examined the validity of adaptive market hypothesis based on data sourced on the Nigerian Stock Market. Our study revealed that the Nigerian Stock Market is inefficient; and that efficiency in the market evolves overtime. We established a link between the stock market behaviour and systemic changes like global financial