The First Tier Securities Market provides a forum for buying and selling of shares of companies in the market. There are for well established large scale. companies. while the Second-Tier Securities Market (SSM) is a second market established by The Stock Exchange to list the securities of smaller companies which are unable to meet the requirements for listing on the more stringent segment (main market) of the Exchange. This means the first tier is more strict and restricted in their activities than the second-tier.