What is a Mainboard IPO?
A Mainboard IPO is a public offering of shares by a company that meets SEBI's stringent eligibility criteria for listing on the main trading platforms of the National Stock Exchange (NSE) and Bombay Stock Exchange (BSE). These are typically large, established companies with a proven track record of profitability, significant revenue scale, and robust corporate governance structures.
To qualify for a mainboard listing, a company must meet several key requirements: a minimum post-issue paid-up capital of Rs 10 crore, at least three years of profitability (net tangible assets of at least Rs 3 crore in each of the preceding three full years), minimum net worth requirements, and a track record of distributable profits for at least three of the preceding five years. These criteria ensure that only companies with established businesses and financial stability can access the mainboard capital markets.
Mainboard IPOs are the headline-grabbing offerings that dominate financial news — companies like Hyundai India (Rs 27,000 crore), Swiggy (Rs 11,000 crore), Hexaware Technologies, and Zomato are all mainboard IPOs. These offerings typically raise Rs 500 crore to Rs 30,000 crore, attract massive institutional participation from mutual funds, insurance companies, and foreign institutional investors (FIIs), and benefit from deep post-listing liquidity.
The regulatory oversight for mainboard IPOs is rigorous. SEBI reviews the DRHP in detail, the company must appoint merchant bankers from SEBI's registered list, and post-listing compliance requirements include quarterly financial reporting, corporate governance disclosures, and adherence to listing regulations. This regulatory framework provides a significant layer of protection for retail investors.
Mainboard IPOs also have a lower barrier to entry for retail investors. The minimum application amount is approximately Rs 13,000 to Rs 15,000 (one lot), making them accessible to virtually any investor with a demat account and a UPI-linked bank account.
What is an SME IPO?
SME IPOs are public offerings by small and medium enterprises that list on dedicated SME platforms — NSE Emerge and BSE SME. These platforms were created by SEBI in 2012 to provide smaller companies with access to capital markets without requiring them to meet the stringent eligibility criteria of mainboard listings.
The eligibility requirements for SME IPOs are significantly relaxed compared to mainboard. A company needs a post-issue paid-up capital between Rs 1 crore and Rs 25 crore (if the paid-up capital exceeds Rs 25 crore post-issue, the company must list on the mainboard). Unlike mainboard IPOs, SME companies can be loss-making at the time of listing — there is no mandatory profitability requirement. The company must have a net worth of at least Rs 1 crore and must have been in existence for at least three years.
SME IPOs are typically much smaller in size — ranging from Rs 5 crore to Rs 500 crore. They attract less institutional participation and have thinner post-listing liquidity. However, they can also deliver extraordinary returns. In 2024 and 2025, several SME IPOs delivered listing gains of 100-200 percent, far exceeding the average mainboard listing gain of 18-22 percent.
The appeal of SME IPOs lies in their growth potential. Many SME companies are in the early stages of their growth journey — entering new markets, scaling production, or building brand recognition. If the company executes its growth plan successfully, early investors (IPO allottees) can see multi-fold returns over two to three years.
However, the risks are proportionally higher. SME companies have limited track records, thinner management depth, higher vulnerability to economic downturns, and significantly lower regulatory oversight compared to mainboard companies. The financial disclosures are less detailed, the audit requirements are less stringent, and there is no mandatory quarterly reporting (only half-yearly). The low liquidity post-listing means that selling large positions can be difficult without significant price impact.
Key Differences — Mainboard vs SME IPO
Here is a comprehensive comparison of mainboard and SME IPOs across every important parameter:
| Parameter | Mainboard IPO | SME IPO |
|---|---|---|
| Exchange platform | NSE / BSE (main board) | NSE Emerge / BSE SME |
| Post-issue paid-up capital | Rs 10 crore or more | Rs 1 crore to Rs 25 crore |
| Minimum issue size | Rs 10 crore+ (typically Rs 500 crore+) | Rs 1 crore to Rs 500 crore |
| Profitability requirement | 3 years of distributable profits | No profitability requirement |
| Minimum application (retail) | ~Rs 13,000 to Rs 15,000 (1 lot) | ~Rs 1,00,000 to Rs 1,50,000 (1 lot) |
| Lot size | Small (typically 30-100 shares) | Large (typically 800-2,000 shares) |
| Allotment method (retail) | Lottery (1 lot per allottee) | Lottery (1 lot per allottee) |
| Allotment method (HNI) | Proportionate (bNII/sNII split) | Proportionate |
| SEBI review | Mandatory DRHP review | Exchange reviews (not SEBI) |
| Underwriting | Partial underwriting allowed | 100% mandatory underwriting |
| Market maker | Not mandatory | Mandatory for 3 years post-listing |
| Financial reporting | Quarterly results mandatory | Half-yearly results only |
| Listing day circuit limit | No circuit limit on Day 1 | No circuit limit on Day 1 |
| Post-listing circuit limit | 5% / 10% / 20% (based on exchange classification) | 5% / 10% / 20% |
| Migration to mainboard | Already on mainboard | After 3 years, if criteria met |
| Liquidity | High (institutional + retail participation) | Low (thin volumes, wide spreads) |
| Risk level | Moderate | High |
| Average listing gain (2025) | 18-22% | 35-50% (with higher variance) |
Lot Size and Minimum Investment
The most significant practical difference between mainboard and SME IPOs is the minimum investment required. Mainboard IPOs are designed to be accessible — SEBI mandates that the minimum application value for retail investors should be approximately Rs 13,000 to Rs 15,000. This translates to small lot sizes of 30 to 100 shares depending on the issue price.
SME IPOs, by contrast, have much larger lot sizes — typically 800 to 2,000 shares per lot. At typical SME issue prices of Rs 50 to Rs 200 per share, the minimum application value ranges from Rs 1,00,000 to Rs 1,50,000 or even higher. This high minimum investment effectively filters out casual retail investors and limits participation to those with greater capital and (ideally) greater market knowledge.
The large lot size in SME IPOs serves a practical purpose — it ensures sufficient trading volumes post-listing. If lot sizes were as small as mainboard IPOs, the already thin liquidity in SME stocks would become even thinner, potentially making the stock virtually untradeable.
Allotment Process Differences
For oversubscribed mainboard IPOs, retail allotment works on a pure lottery basis — each valid application has an equal chance of receiving exactly one lot, regardless of the number of lots applied for. This means applying for 1 lot gives you the same probability as applying for 13 lots (the typical maximum within the Rs 2 lakh retail limit).
SME IPOs follow a similar lottery system for retail applications. However, since the minimum application itself is Rs 1 lakh or more, the retail pool in SME IPOs is much smaller than in mainboard IPOs. This can result in either higher or lower allotment probabilities depending on the specific IPO's subscription level.
For the NII/HNI category, both mainboard and SME IPOs use proportionate allotment. However, mainboard IPOs have the bNII (big NII, Rs 10 lakh to Rs 2 crore) and sNII (small NII, Rs 2 lakh to Rs 10 lakh) sub-categories introduced by SEBI in 2022. SME IPOs do not always have this split.
Liquidity Differences
Post-listing liquidity is perhaps the most underappreciated difference between mainboard and SME IPOs. Mainboard stocks benefit from deep institutional participation — mutual funds, insurance companies, FIIs, and proprietary trading desks all trade these stocks actively. Daily trading volumes for mainboard-listed IPO stocks typically range from Rs 10 crore to Rs 500 crore, ensuring that investors can buy or sell at any time without significantly impacting the price.
SME stocks, by contrast, often have daily trading volumes of just Rs 10 lakh to Rs 1 crore. Some SME stocks may go entire days without a single trade. This means that if you want to sell a significant position in an SME stock, you may not find buyers at your desired price. The bid-ask spread (the difference between the highest buy price and the lowest sell price) can be 3-5 percent or more, compared to 0.01-0.1 percent for liquid mainboard stocks.
SME stocks are also subject to the mandatory market maker requirement. SEBI mandates that a market maker must provide continuous two-way quotes for at least 75 percent of the trading day for the first three years after listing. This provides a minimum level of liquidity, but the market maker's obligation is limited to small lot sizes and may not be sufficient for investors looking to exit large positions quickly.
Who Should Apply for SME IPOs?
SME IPOs are not for everyone. They are most suitable for:
- Experienced investors who understand fundamental analysis and can evaluate small companies with limited financial disclosures. If you cannot read a balance sheet or do not understand P/E ratios, SME IPOs are not for you.
- Investors who understand the sector in which the SME operates. Domain expertise gives you an edge in evaluating whether the company's growth claims are realistic.
- Investors who can afford the minimum lot size (Rs 1 lakh+) without it representing a disproportionate share of their portfolio. Never allocate more than 5-10 percent of your total equity portfolio to any single SME IPO.
- Long-term holders who can commit capital for 1-2 years. SME stocks often take time to deliver returns as the company executes its growth strategy. Short-term trading in SME stocks is risky due to low liquidity.
- Risk-tolerant investors who accept the possibility of losing a significant portion of their investment. Unlike mainboard IPOs where total loss is rare, SME companies can and do fail, resulting in 50-80 percent capital erosion.
How to Migrate from SME to Mainboard
SME companies are not permanently confined to the SME platform. SEBI provides a pathway for successful SME companies to migrate to the mainboard, which unlocks significantly greater liquidity, institutional participation, and investor confidence.
The migration process typically happens after three years on the SME platform. To qualify, the company must meet the mainboard eligibility criteria at the time of migration: post-issue paid-up capital exceeding Rs 10 crore, minimum three years of profitability, adequate net worth, and compliance with all mainboard corporate governance requirements.
The migration process involves filing an application with the stock exchange, obtaining shareholder approval (via special resolution), and completing the due diligence process. Once approved, the company's shares move from the SME platform to the mainboard, and the stock becomes available to a much wider pool of investors.
Migration is a significant positive catalyst for SME stocks. Companies that successfully migrate typically see a 20-50 percent appreciation in stock price around the migration event as institutional investors who were previously unable or unwilling to buy SME stocks enter the stock. Historical data shows that companies that grow from SME to mainboard deliver some of the highest multi-year returns in the Indian equity market.
Key Takeaways
- Mainboard IPOs are issued by large, established companies (Rs 10 crore+ paid-up capital, 3 years of profitability required) and list on the main NSE/BSE platforms with high liquidity
- SME IPOs are issued by smaller companies (Rs 1-25 crore paid-up capital, no profitability requirement) and list on NSE Emerge or BSE SME platforms with low liquidity
- The minimum investment for mainboard IPOs is approximately Rs 13,000-15,000, while SME IPOs require Rs 1,00,000 or more per lot
- SME IPOs can deliver higher listing gains (35-50 percent average in 2025) but with significantly higher risk and variance compared to mainboard IPOs (18-22 percent average)
- Post-listing liquidity is the most critical practical difference — mainboard stocks trade freely while SME stocks may have very thin volumes and wide bid-ask spreads
- SME IPOs are suitable only for experienced, risk-tolerant investors who can commit capital for 1-2 years and can afford the large minimum lot size
- Successful SME companies can migrate to the mainboard after 3 years, which is often a major positive catalyst for the stock price
Disclaimer: This article is published by ipomarket.in for educational and informational purposes only. It does not constitute investment advice, a recommendation to buy or sell any security, or an offer to invest. IPO investments are subject to market risks. Grey Market Premium (GMP) data is sourced from unofficial market participants and is not endorsed by SEBI, NSE, or BSE. Past performance is not indicative of future results. Please read all scheme-related documents carefully and consult a SEBI-registered financial advisor before investing. ipomarket.in is not a SEBI-registered investment advisor or research analyst.