A stock market functions efficiently through a network of intermediaries who facilitate trading, investor services, and regulatory compliance. Among these intermediaries, Stock Brokers, Sub-Brokers, and Authorised Persons perform distinct roles. Their responsibilities, authority, and relationship with stock exchanges and investors differ significantly. A Stock Broker is a person or corporate entity registered with the Securities and Exchange Board of India (SEBI) and admitted as a member of a recognized stock exchange. A stock broker acts as an intermediary between investors and the stock exchange for buying and selling securities. Brokers execute trades on behalf of clients, provide investment-related services, maintain trading accounts, collect margins, settle transactions, and ensure compliance with regulatory requirements. They have direct access to the trading platform of stock exchanges and are responsible for maintaining proper books of accounts, investor records, and risk management systems. Stock brokers earn income through brokerage charges, commissions, and fees for value-added services. A Sub-Broker is a person or entity who acts as an intermediary between a stock broker and investors. A sub-broker is not a direct member of the stock exchange but works under a registered stock broker. The primary responsibility of a sub-broker is to procure clients, assist them in opening trading and demat accounts, collect and forward orders to the stock broker, provide customer support, and educate investors regarding market operations. The actual execution of trades takes place through the stock broker's trading terminal. The sub-broker receives a share of the brokerage earned by the stock broker based on their mutual