This paper has investigated the weak form efficiency of the Nigerian Stock Exchange (NSE) through a test for random fluctuations in series of stock prices on the Nigerian Stock Exchange between the 2000 and 2007. The decision to focus on this period was informed by the fact that the NSE enjoyed a market boom during this period prior to the recent global economic crunch. The study is an ex-post facto study that employed the runs test in analyzing the monthly stock index from January 2000 to December 2007. The result from this study points to the non-existence of random fluctuations in series of price of stocks traded on the NSE, thus this work concludes that the series of price of stocks traded on the NSE between 2000 and 2007 did not follow random fluctuations. This implies that the market was not efficient in the weak form during the period covered by this study.
Keywords: Efficient Market Hypothesis, Nigerian Stock Exchange, Random Fluctuations, Runs Test, Securities, Weak Form Efficiency