What Is GMP in IPO? Meaning, How It Works and Its Risks

GMP, or grey market premium, is the extra amount people are willing to pay over an IPO's price to get its shares before they list on the stock exchange. If an IPO is priced at ₹100 and its GMP is ₹20, the grey market expects the share to open at around ₹120 on listing day.

That is the whole idea in one line. But GMP is also one of the most misunderstood numbers in the Indian market. It is unofficial, it changes every few hours, and it has been wrong many times. So in this guide, I will explain what is GMP in IPO in simple words, how to read it, why it moves, and how to use it without getting fooled.

What is GMP in IPO?

When a company launches an IPO (initial public offering), it sells its shares to the public for the first time. You apply during the IPO window, shares are allotted, and a few days later the shares start trading on the NSE and BSE.

Between the IPO opening and the listing day, there is a gap. In that gap, an informal market runs outside the stock exchanges. This is called the grey market. Dealers in this market quote a price at which they are ready to trade the IPO's shares, even though the shares have not listed yet.

The GMP is simply the difference between that grey market price and the IPO's issue price.

• If the grey market price is higher than the issue price, the GMP is positive. People expect the share to list at a gain.

• If it is lower, the GMP is negative. People expect the share to list below its issue price.

• If there is no demand at all, the GMP is zero or not quoted.

Think of it like the "black" price of a cricket match ticket before a big final. The official ticket may cost ₹2,000, but if everyone wants to go, people outside may pay ₹3,000 for it. That ₹1,000 extra is the premium. GMP works the same way for IPO shares.

How to calculate the expected listing price from GMP

The maths is simple.

Expected listing price = upper end of the price band + GMP

Expected listing gain (%) = GMP ÷ issue price × 100

Let us take an example. Priya is looking at an IPO with a price band of ₹95 to ₹100 and a lot size of 150 shares. One lot costs 150 × ₹100 = ₹15,000.

Here is how the picture changes as the GMP moves during the IPO week. These are made-up numbers, only to show the calculation:

See how the same IPO looked like a 28% gain on day 2 and almost nothing by listing day? That is why a single GMP number, seen once, tells you very little. You can follow the GMP of every live IPO through the day on RupeeVerse IPO Verse.

What are kostak rate and subject to sauda?

You will often see two more grey market terms next to GMP. Both are about selling your whole IPO application, not the shares.

Kostak rate

Kostak is a fixed amount a dealer pays you for your IPO application, whether or not you get shares in the allotment. Say the kostak rate is ₹500. You agree to sell your application, you get ₹500, and if you are allotted shares, the dealer takes the profit or loss from them.

Subject to sauda

Subject to sauda is a deal where the dealer pays you a fixed amount only if you get an allotment. If you get no shares, there is no deal. Because the dealer pays only for allotted applications, this rate is usually higher than kostak.

Both are private deals based on trust. There is no contract you can take to anyone if the other side does not pay.

Why does GMP go up and down?

GMP is a mood meter, not a calculation. It rises and falls with what people expect on listing day. The usual reasons:

1. Subscription numbers. When an IPO is subscribed many times over, especially by big institutions (the QIB category), the GMP usually rises. Weak demand pulls it down.

2. The overall market. If the Nifty and Sensex fall sharply during the IPO week, listing expectations cool off, and GMPs of almost every IPO drop.

3. News about the company. A strong anchor investor list, a big order win or a negative news report can move the GMP within hours.

4. Size of the IPO. In small SME IPOs, very few shares change hands in the grey market. A handful of deals can push the GMP up or down sharply.

5. Hype. Social media buzz can inflate the GMP well beyond what the business justifies.

Is GMP reliable? Why it can go wrong

GMP gives you a rough sense of demand. It is not a forecast you can trust, for a few reasons.

• It is unofficial. There is no exchange, no order book and no public record. Different websites often show different GMPs for the same IPO at the same time.

• It can be pushed up. With so little trading, a few people can move the number, and a high GMP can pull more people into applying.

• The real price is found on listing day. On listing day, the stock exchanges run a special pre-open session where buyers and sellers place orders and the opening price is worked out from those orders. That price can be far from the last GMP.

• The gap is short but eventful. Since December 2023, SEBI has required shares to list within three working days of the IPO closing, known as T+3. A lot can change in those three days, in the market and in the grey market.

One more thing to remember: past GMPs and past listing gains are history. They are not a promise of what the next IPO will do.

Is grey market trading legal? What SEBI says

SEBI does not recognise or regulate the grey market. Deals happen between private dealers, usually in cash, without any exchange or clearing corporation in the middle. So if a dealer does not pay you, or you do not get what was promised, there is nowhere official to complain.

SEBI has spoken about this gap. In 2025, the regulator said it was looking at a regulated platform where investors could trade allotted IPO shares in the days between allotment and listing, a "when-listed" market run with the stock exchanges, as reported by Business Standard. Until such a regulated market is in place, any grey market deal remains unofficial and at your own risk.

How to use GMP sensibly

GMP can be one small input. It should never be the reason you apply. Here is a simple way to think about it:

1. Read what the company does first. The red herring prospectus (RHP) explains the business, its profits, its debts and what the IPO money will be used for.

2. Look at who is applying. Strong demand from QIBs, the big institutions that study companies closely, often says more than GMP.

3. Follow the GMP trend, not one number. A GMP that falls steadily through the week tells a different story from one that holds steady.

4. Never borrow to apply because the GMP looks high. Listing gains are never guaranteed.

5. Know the tax. If you sell your shares after listing, the profit is taxed as capital gains. You can work it out with the capital gains calculator.

Key takeaways

• GMP is the unofficial premium over an IPO's price at which its shares trade before listing.

• Expected listing price = upper price band + GMP.

• GMP changes with subscription, market mood and news, often within hours.

• The grey market is not regulated by SEBI, and grey market deals have no protection.

• Use GMP as one rough signal, next to the company's RHP and the subscription data, never on its own.

If you want to watch how GMP moves for every mainboard and SME IPO, keep IPO Verse open during the IPO week. And if you are new to IPOs, start with the basics before you apply to your first one. Understanding the number is always better than chasing it.