This research work is on the impact of The Nigerian Securities Exchange Market and the Nigerian Economy. The main objective of this study is to empirically examine the impact of Nigerian Securities Exchange Market and the Nigerian Economy: A Test of the Adaptive Expectation Hypothesis. This research work made use of secondary data which were obtained from the Central bank of Nigeria Statistical Bulletin (2015). The data were collected for a period of twenty six years (i.e. 1990-2015). The Ordinary Least Square Regression Technique was employed in the analysis of the data. Based on the empirical analysis, it is concluded that security and exchange market has significant impact on gross domestic product in Nigeria. It is therefore recommended that; The funds raised by government in the form of government securities in the capital market should be put into productive sectors of the economy that will necessitate to growth in all facets of the economy and hence bring about job creation vis a vis increase in standard of living.