In the Indian stock market, a Mainboard IPO refers to the initial public offering of a large, well-established company that lists its shares on the primary trading platforms of the National Stock Exchange (NSE) or the Bombay Stock Exchange (BSE). Unlike SME (Small and Medium Enterprise) IPOs, which are designed for smaller businesses with relaxed norms, Mainboard IPOs are intended for major corporations with significant scale and a proven financial track record. To qualify, SEBI (Securities and Exchange Board of India) mandates strict criteria, including a minimum post-issue paid-up capital of ₹10 crore and a history of consistent profitability, typically requiring an average operating profit of at least ₹15 crore over the preceding three years.

These offerings are highly regulated and require the company to file a detailed Draft Red Herring Prospectus (DRHP) for thorough vetting by SEBI to ensure transparency and investor protection. For retail investors, Mainboard IPOs are generally considered more accessible and stable, with a minimum application amount usually ranging between ₹14,000 and ₹15,000. Once listed, these stocks offer high liquidity due to massive trading volumes and participation from large institutional investors, mutual funds, and foreign portfolios. Ultimately, a Mainboard IPO serves as a gateway for mature companies to raise substantial capital for expansion while providing the public with a chance to own shares in established market leaders.