Many large companies are going public on the main board exchange. The companies are raising a lot of money from the public and institutional investors via an IPO. The size of the issue provides investors with an idea of how big the public offering is. This article provides the biggest IPO of 2026 and the list of top 10 IPOs by their total issue size in the mainboard category.
What is Mainboard IPO and Issue Size?
An Initial Public Offering (IPO) is the first time a private company issues shares for sale to the public. The company lists its shares on major stock exchanges like the National Stock Exchange and Bombay Stock Exchange. A mainboard public offering is meant for established large companies that have large operations and a net worth.
The size of the issue is the amount of money that a company wants to raise from investors in the public issue. The amount is calculated by multiplying the total number of shares offered with the price of each share. A large issue size indicates that the company needs a lot of money to expand or reduce its debts. It also informs investors about the volume of shares that will enter the open market for trading.
Factors Affecting Mainboard IPO Issue Size
Before determining the total amount of a public offering, corporate boards consider various financial issues. Each business is based on particular strategies that need a large amounts of capital funds that they raise through Mainboard IPO issue..
- Expansion Requirements – Businesses require capital to expand their production facilities or establish storage facilities in various parts of the country. They calculate the total amount of cash needed for these physical arrangements and determine a portion to raise from retail citizens. Large expansion projects always increase the final target size of a public issue.
- Promoter Stake Sale – Existing owners often want to sell their share of the company in order to book corporate profits after years of hard work. This is known as an offer for sale, and the funds are deposited in the promoters’ pockets rather than company accounts. The larger the stake sale by the old investors, the larger the total issue size of that particular mainboard asset.
- Working Capital Needs – Large companies need cash flow every day to keep the business running smoothly and to keep the inventory levels high without the need to take out high-interest loans. They pay off their short-term liabilities with public funds and manage their business operations without cash crunch problems. This objective is added to the total fund objective, which is mentioned in the official prospectus papers of the company.
List of Top 10 IPOs by Issue Size (Mainboard) – Biggest IPO in 2026
The following table summarizes all key information on the biggest IPO in 2026 that have entered the mainboard market this year. It contains important factors such as listing date, pricing, subscription level and the grey market premium of the top 10 IPO by issue size..
| IPO Name | Issue Size | IPO Price | Subscription | Listing Price | Listing Gain | Listing Date |
|---|
| Raajmarg Infra Investment Trust | 6000 | 100 | 13.74x | 107 | 7% | Mar 24 2026 |
| Bagmane REIT | 3405 | 100 | 24.96x | 103.50 | 3.5% | May 14 2026 |
| Clean Max Enviro Energy Solutions | 3079.88 | 1,053 | 0.99x | 960 | -8.83% | Mar 02 2026 |
| Fractal Analytics | 2833.9 | 900 | 2.81x | 876 | -2.67% | Feb 16 2026 |
| Shadowfax Technologies | 1907.27 | 124 | 2.86x | 112.60 | -9.19% | Jan 28 2026 |
| Central Mine Planning | 1841.45 | 172 | 1.05x | 160 | -6.98% | Mar 30 2026 |
| Amagi Media Labs | 1788.62 | 361 | 30.24x | 318 | -11.91% | Jan 21 2026 |
| Citius Transnet InvIT | 1105 | 100 | 20.43x | 104.60 | 4.60% | Apr 29 2026 |
| Powerica | 1100 | 395 | 1.53x | 366 | -7.34% | Apr 02 2026 |
| SEDEMAC Mechatronics | 1087.35 | 1,352 | 2.68x | 1535 | 13.54% | Mar 11 2026 |
Steps to Apply for Mainboard IPOs
Easily, in minutes, retail investors can place bids for these large, public assets via electronic trading applications. The system operates digitally with banking verification portals.
To safely keep corporate shares, an individual needs to have a demat account with a registered stockbroker in India. The broker will confirm your Permanent Account Number card information as well as your active bank account paperwork. This process takes 24 hours to activate your unique central identity for trading shares.
- Click on the Public Issue button
You should go to your broker application and then to the initial public offering tab on the dashboard screen. The screen will list all open issues that are accepting money applications from retail public users currently. You have to choose the particular company name that you want to purchase for your own personal portfolio.
Each mainboard issue has a fixed minimum quantity of shares that need to be purchased in a single lot. You will choose the number of lots and enter your bid amount at the highest cut-off price limit. This option will keep your application valid during the final share distribution by registrar offices.
The system will request your virtual payment address to send a block request to your linked bank account. In order to open your banking application and authorise the funds block command, you will need to enter your secret pin number. This money will be safely kept in your bank account until the last allocation date.
Also Read:
IPO Application
Conclusion
In 2026, biggest IPO list shows that the market is seeing a record number of fund collections from corporate giants. Investors are provided with a clear platform to be partners to emerging industries such as technology, finance and green mobility. Individuals should study the total issue size along with subscribers’ trends monitored regularly, and this enables people to make better decisions for the Mainboard IPO investment in the volatile financial market.
How much is the minimum investment for mainboard IPO?
It costs approximately ₹14,000-15,000 for an individual to buy one application block of a mainboard issue. For retail users, the exchange determines the number of shares that will fit into this particular cash range.
Where can I get the subscription data for a live public issue?
One can check the live subscription numbers on the official stock exchange platforms or online applications of share brokers. These updates are updated hourly when the bidding is open during the working days. IPO INDEX provides accurate Subscription data, too.
What does Grey Market Premium mean in share trading?
The extra price that traders are willing to pay for the shares in an unofficial cash market before they are listed is known as the grey market premium. It reveals the general market mood and demand for that public asset prior to the official market trading.
Why do companies choose the mainboard route instead of the SME segment?
Large corporations have already made a lot of profits and need a lot of capital, which is not suitable for small enterprise platforms. The listing on the mainboard provides them with access to international funds and to larger institutional investors around the world.
Can I apply for a public issue using more than 1 demat account with the same PAN?
To maintain the fair share distribution rules, the registrar system rejects multiple applications with the same permanent account number. To boost your chances of allotment success, you should use accounts with different family members.
What happens to my money if I do not receive any share allocation?
Your bank will release the blocked money automatically within two working days after the final selection process finishes. The cash remains safe in your own savings account during the entire period of the public issue.
Is it safe to buy a public issue that has a very small subscription rate?
Low subscription rates show that large funds and common public buyers are not showing interest in that specific business issue. It can lead to low demand or negative prices on the final trading debut day.
How many days does it take for a mainboard IPO to list after closing?
Mainboard IPO complete the distribution process and lists on national stock exchanges within three working days after the public bidding window shuts down. This swift timeline protects investor capital from long blocking periods.
What is the role of a registrar in a public offering process?
The registrar is an independent corporate body that collects all digital bids and manages the allotment process accurately based on rules. They handle financial refunds and transfer equity shares to the demat accounts of successful applicants.
Can a retail investor sell shares on the exact morning of the listing day?
An investor can sell allocated shares right from 10 o’clock in the morning on the official debut day when normal market trading starts. The pre-open session determines the final opening price of that share before regular trading hours.