SME IPO vs Mainboard IPO: The Key Differences Explained
Reviewed by Kanishk Dev Bangia, NISM Series XV Certified Research Analyst Last Updated: June 2026 | Reg. No: NISM-202300182946
The phrase “going public” tends to conjure images of a streamlined procedure for doing so. In the context of analyzing the methods Indian firms use to reach the general public markets, there is one crucial aspect which continues to elude me despite my best efforts at understanding. Specifically, an IPO could either be conducted under the auspices of the mainboard or SME (small and medium enterprises) platform, and these are distinct processes with distinct requirements.
This guide will examine some of the differences that exist between SME IPO and mainboard IPO. Eligibility, issue size, lot size, listing platform, liquidity, disclosure load, and migration to main board are some of the topics which we will examine in this guide. Also, I’ll attempt to tie it to the unlisted/pre-IPO market, since a large proportion of these firms would have been actively traded prior to conducting their IPOs. All figures stated below are for illustration only – please check the actual values from primary sources.
1. What “SME” and “Mainboard” Actually Mean
The “Mainboard” represents the core listing segment of the main exchanges. When a well-established company is listed on this segment, it is alongside the well-known stocks that you have heard of before.
The SME segment, on the other hand, is another special listing segment which has been created specifically to allow smaller and emerging companies to access public funds without needing to satisfy the high requirements of the mainboard listing. The BSE and NSE both have their own segments of this nature known as the BSE SME and NSE Emerge segments, respectively. These are market infrastructure segments and NOT companies; they exist purely because a one-size-fits-all approach to listing is unfair to smaller companies.
So the first thing to keep in mind about this subject: An SME listing and a Mainboard listing are NOT variations of the same product in different sizes. They are two different regulatory streams, with different rule books regulated by SEBI through the exchange.
2. Eligibility: Who Can Use Each Route
The mainboard path is geared towards companies that have already achieved tougher hurdles — generally, greater paid-up capital, longer track record of operation and profitability, and capacity to handle extensive disclosures and compliance. Due diligence for a mainboard listing is very thorough, and the obligations placed upon the merchant banker in this regard are quite rigorous.
The SME path actively makes some of these hurdles easier. Paid-up capital limits will be lower post-issue, track record requirements are reduced, and the whole process of gaining approval should be both quicker and more economical. The goal is to provide an opportunity — allowing a company which is profitable but continuing to grow to raise money from the public without the whole mainboard process.
I just want to make one point clear at this stage. I am talking about the general form of the difference in eligibility, not citing actual figures. Eligibility requirements with respect to the amount of paid-up capital, track record period, and other conditions set by the exchange and/or SEBI are reviewed periodically and updated accordingly.
3. Issue Size: The Most Visible Gap
The most obvious practical distinction is the amount of money involved. A mainboard IPO tends to be relatively large, in order to make it worthwhile for the firm to undertake the entire process and allow for widespread public participation.
The nature of an SME listing means that it will be relatively small. An emerging company which does not require a lot of money to fuel its expansion will likely find a mainboard listing prohibitively costly and time-consuming.
It follows from this point on to nearly all other factors – the quantity of shareholders, marketing of the issue, anchor participants, as well as post-listing share trading.
4. Lot Size and Minimum Application
And here's where retail investors will really be able to feel the difference. For the mainboard, the application lot size is designed such that each retail lot size is quite low on a minimum ticket basis — the idea being to attract the largest possible number of retail participants.
For the SME segment, the minimum lot size is higher by design, which means the minimum ticket size required to participate is also higher. This is an attempt to limit participation to investors who are more capable of absorbing higher minimum tickets as well as understanding the risk involved in such securities.
This implies that, in general, a retail investment for an SME IPO would involve a higher cheque size as compared to a similar mainboard retail investment — a relative comparison in terms of trend, not in absolute terms of rupees. Once listed, the SME stock is likely to trade in multiples of such lot sizes.
5. Listing Platform and Trading Mechanics
In a main board IPO, the listing is done in the main board itself and the IPO is traded just like any other large-cap or mid-cap stock. Single share trading takes place with huge depth and continuous price discovery based on participation from various participants.
In the case of SME IPOs, the listing takes place in the SME boards, BSE SME or NSE Emerge. The difference lies in the trading aspect where trading takes place in large prescribed lot sizes. One of the unique aspects of such stocks would be the mandatory market making system since the pool of buyers and sellers is limited in nature. This means that in the absence of such an arrangement, there is a very good possibility that the SME stock may lack any trading interest.
One single design feature of SME stocks explains everything about them – liquidity cannot be taken for granted.
In summary: SME stocks list on BSE SME/NSE Emerge, trade in large lot sizes and utilize mandatory market makers for liquidity.
6. Disclosure and Compliance Intensity
The disclosure obligations on mainboard companies are most onerous; from regular and detailed disclosures, good governance, all the way to ongoing responsibilities after listing. In turn, the offer document for mainboards is equally detailed and thorough.
While SMEs have a lighter touch to them, there’s no doubting that the obligation remains significant. The disclosure obligations and reporting requirements will be streamlined compared to the mainboard, but this is intentional in order to prevent being listed from overwhelming smaller businesses. This is indeed an important trade-off for investors since lighter disclosure translates into less data to work with, which helps explain why the framework requires a larger minimum ticket size and an investor aware of risks.
Regardless of which path the company chooses, there’s always one document that holds significance — the offer document (draft red-herring prospectus, or DRHP). Never read one before? My accompanying piece on reading DRHP explains what you need to know and what you don’t.
7. Liquidity and the Investor Profile
All of this considered together shows the liquidity difference quite clearly. Stocks on the mainboard tend to have good liquidity – significant free float, wide ownership, and lots of buyers and sellers ready to trade.
Smaller stocks have inherently poor liquidity conditions due to smaller stocks themselves, greater lot multiple, and a relatively narrow circle of potential buyers. As a result, the difference in investor type each stock listing attracts comes as no surprise. While the mainboard has all types of individual investors, the SME segment tends to attract those who like concentrating, being prepared for low liquidity, and investing in high-volatility stocks.
Once again, none of these is better, but one should know which path they choose to follow.
8. The SME-to-Mainboard Migration Path
One of the most useful features of the SME platform is that it isn’t a dead end. An SME-listed company that grows — crossing the size and track-record thresholds and meeting the prescribed conditions — can migrate from the SME segment to the mainboard. The exchanges and SEBI lay out the eligibility and process for this graduation.
Migration matters because it changes the stock’s entire profile: it moves to single-share trading on the main segment, typically sees broader investor participation, and steps up into the fuller disclosure regime. For long-horizon observers, the migration milestone is a meaningful marker of a company maturing from a small-cap growth story into an established main-board name. It is not automatic or guaranteed — it depends on the company continuing to qualify and choosing to make the move.
9. Where Unlisted / Pre-IPO Holders Sit
Before any of this — SME or mainboard — many of these companies traded in the unlisted / pre-IPO market. Employees with ESOPs, early investors, and buyers in the private secondary market hold shares while the company is still private.
When such a company eventually files for an IPO, the route it chooses (SME vs mainboard) shapes what that liquidity event looks like for those holders. A mainboard listing generally opens a deep, liquid market to exit into; an SME listing opens a thinner one with larger lots and market-maker-supported trading. Pre-IPO holders should also note that listings usually come with lock-in obligations on certain pre-IPO shareholders, so “the company listed” does not always mean “I can sell today.” The mechanics of acquiring shares in that private phase — and how the holding then carries through to listing — are covered in how to buy unlisted shares in India.
Lesson: The IPO route a private company picks defines the exit landscape for its existing unlisted and pre-IPO holders.
Frequently Asked Questions
Is an SME IPO riskier than a mainboard IPO?
Structurally, SME issues tend to involve smaller, younger companies with lighter disclosure and thinner post-listing liquidity, which generally implies a higher-risk profile. That’s a description of the framework, not a verdict on any specific issue — risk always depends on the individual company.
Why is the SME IPO lot size so much bigger?
The larger minimum lot is a deliberate suitability filter. Because SME issues carry more concentrated risk and thinner liquidity, the framework nudges participation toward investors willing and able to commit a bigger single ticket. The figures are set by the exchanges and revised over time.
What is a market maker in an SME IPO?
A market maker is a designated participant (usually arranged via the merchant banker) obligated to provide two-way buy and sell quotes for a defined period after an SME listing, so the stock has some baseline tradability despite a naturally thin pool of buyers and sellers.
Can every SME company move to the mainboard?
No. Migration is available only to SME companies that grow into the prescribed size, track-record, and other eligibility conditions and choose to migrate. It is neither automatic nor guaranteed, and many companies remain in the SME segment.
Disclaimer:
This is written for educational and informational purposes only. Nothing here constitutes investment advice or a recommendation to buy or sell securities. All data is sourced from publicly available information. Investments in securities markets are subject to market risks — please read all offer documents carefully before investing.
