A Stock Broker, Sub-Broker, and Authorised Person are important intermediaries in the securities market. They facilitate trading in securities and help investors access stock exchanges. Although all three are involved in the distribution of brokerage services, they differ significantly in terms of legal status, regulatory recognition, authority, responsibilities, and relationship with investors. Understanding these distinctions is essential for comprehending the functioning of the Indian securities market under the regulatory framework of the Securities and Exchange Board of India (SEBI). A Stock Broker is a person or corporate entity registered with SEBI and admitted as a member of a recognized stock exchange. A stock broker acts as the principal intermediary between investors and the stock exchange. Since investors cannot directly trade on the exchange, they execute transactions through registered stock brokers. A broker is authorized to buy and sell securities on behalf of clients and earn brokerage as compensation for the services rendered. Stock brokers perform various functions such as executing buy and sell orders, maintaining trading accounts, ensuring compliance with regulatory requirements, providing investment research, facilitating settlement of trades, collecting margins, maintaining client records, and resolving investor grievances. They are responsible for complying with SEBI regulations, exchange rules, anti-money laundering guidelines, Know Your Customer (KYC) norms, and investor protection measures. The liability for client transactions primarily rests with the stock broker. The broker maintains direct contractual relations with clients and is accountable for all trading activities conducted through its terminals. Stock brokers are required to maintain adequate capital, infrastructure, qualified personnel, and technological systems to ensure smooth trading operations. A Sub-Broker was historically an intermediary who acted on behalf of a registered stock broker rather than being a direct member of the stock exchange. A sub-broker was registered with SEBI and worked under the supervision and control of a principal broker. The sub-broker introduced clients to the broker, collected orders, assisted investors in completing documentation, and facilitated trading services. Unlike stock brokers, sub-brokers could not directly execute trades on the stock exchange. All transactions had to be routed through the stock broker with whom the sub-broker was affiliated. The sub-broker earned a share of the brokerage generated from client transactions. The sub-broker maintained close contact with investors, especially in semi-urban and rural areas where the principal broker might not have a physical presence. This arrangement helped expand the reach of stock market services and improve financial inclusion. However, following regulatory reforms by SEBI, the concept of sub-broker registration has largely been discontinued and