Stock market has emerged as one of the well-known powerful areas due to economic globalization as well as representing the overall economic growth of the country. In the past two decades, there were many research efforts have been put by various researchers and academicians in the field. The major problem of the stock market is that it embodies the vast amount of knowledge of different sectors at one place and representation of this knowledge is very chaotic. In this direction, an expert system is a powerful concept which supports an intelligent decision making process as well as knowledge representation techniques. This study mainly highlights the expert system design and development in the stock market field based on forward reasoning approach. However, the inference engine is tested for nine different shares of Bombay Stock Exchange (BSE) index of India like Infosys, TCS, ONGC LTD., Reliance Industry, Wipro LTD., Asian Paints, Ambuja Cement, HCL LTD., and HDFC LTD. The Common Lisp 3.0 editors are used in the expert system design task. Finally, experimental results showed that system could have the capability to predict the stock price pattern accurately.