Grey Market Premium (GMP) Explained: Why It Can Be a Trap for Indian IPO Investors
Open any IPO discussion on Reddit or a Telegram group and the first question is almost always the same: "What's the GMP?" The grey market premium has become the number Indian retail investors check before they apply, treating it as a preview of listing-day profit. It is also the number more experienced investors keep warning newcomers about. The common refrain in retail forums is blunt: GMP can be a trap.
This guide explains what GMP really is, who sets it, why it sits outside any regulator's reach, and what recent listing data shows about how often it is wrong. The goal is not to tell you to ignore GMP, but to use it for what it is, and not for what it pretends to be.
What grey market premium actually is
Grey market premium is the extra amount, over and above the IPO issue price, that buyers in an informal market are willing to pay for shares before they list on the exchange. If an IPO is priced at ₹100 and the GMP is ₹40, the grey market is implying a listing around ₹140, a 40% gain.
The "grey market" is a network of dealers and investors who trade IPO applications and yet-to-be-listed shares among themselves, before the stock is officially available. It is older than the apps that now display it. Two things trade in it: the shares themselves (priced via GMP) and the application, or "kostak" and "subject to sauda" rates.
For our purposes the key point is simpler. GMP is a sentiment indicator, a read on how much demand exists in a small, informal pool of traders. It is not a price set by an exchange, a forecast from an analyst, or a number anyone is accountable for.
Who sets GMP, and how
This is where most retail investors are surprised. There is no single source for GMP. As one explainer puts it, the figure is "crowd-sourced from brokers and participants active in the grey market", and is "an estimate, not an official figure."
The numbers you see on tracker websites are aggregated reports from grey market dealers, mostly concentrated in a few trading hubs. Someone phones around, collects the rates being quoted, and publishes a figure. Different sites often show slightly different GMPs for the same IPO on the same day, which alone tells you how soft the number is.
There is no electronic order book, no central clearinghouse, and no audit trail. You cannot see the volume behind a GMP, so you cannot tell whether it reflects a thousand trades or a handful. That gap matters a great deal, as the next section shows.
Why GMP can be a trap
1. It is unregulated, and trades are not enforceable
The grey market operates entirely outside the formal system. There are no official exchanges, no SEBI oversight, and no legal contracts. SEBI does not recognise or settle grey market trades and has cautioned investors against taking part. If a counterparty defaults on a deal, there is no legal recourse.
For a retail investor who is only reading the GMP rather than trading in it, the takeaway is this: you are leaning on a number produced by a market with no rules and no accountability.
2. A few trades can move it, especially for small IPOs
Because there is no volume data, a thin grey market is easy to push around. As one analysis notes, "for smaller IPOs, GMP can be set by very few transactions. A single large buyer pushing up the grey market price can create a misleading GMP."
This is sharpest in SME IPOs, where the grey market is thinnest. Promoters or operators sometimes inflate GMP deliberately to manufacture FOMO, drawing in retail money on the promise of a big listing pop. Plenty of high-GMP SME issues have gone on to list flat or at a discount.
3. The accuracy is weaker than it looks
Here is what the data actually says. Studies of Indian IPOs put GMP's directional accuracy at roughly 60-70% for large-cap IPOs. That is, it gets the direction (gain or loss) right about two times in three. It is weaker still for SME issues. Directional accuracy is not the same as predicting the listing price; GMP is far less reliable at telling you how much a stock will move than whether it will move up or down.
The 2025 cycle made the gap obvious. Nearly a third of mainboard IPOs in 2025 listed below the gains their peak GMP had implied, even for heavily oversubscribed issues. Average listing gains fell to about 10% in 2025, down from roughly 30% in 2024, while GMPs in many cases stayed elevated right up to listing.
4. GMP often peaks and then collapses
GMP is not a fixed number; it moves daily, sometimes hourly, on rumour and sentiment. The danger is that retail investors anchor to the peak GMP they saw during the subscription window, not the deflated number at listing.
Two recent examples make this concrete. Lenskart's GMP collapsed by roughly 90% before listing. Tata Capital's GMP implied a 6-7% listing gain, but the stock actually opened with only a 1.2% premium. In both cases an investor who applied chasing the early GMP would have been badly misled about the outcome.
What GMP is genuinely useful for
None of this means GMP is worthless. Used carefully, it is a reasonable sentiment gauge:
- Direction over magnitude. A clearly positive GMP that holds steady through the subscription period is a fair signal that the market expects a positive listing. Treat the direction as the signal and ignore the precise rupee figure.
- Relative demand. GMP is more informative when compared with subscription data. Issues with strong GMP have tended to see far higher retail oversubscription, but that is a measure of hype, not of business quality.
- A starting point, not a verdict. GMP can tell you what the crowd feels today. It cannot tell you whether a company is worth owning.
How to use GMP without getting trapped
- Never apply on GMP alone. Read the company's fundamentals: revenue, profitability, valuation, and the risks in the DRHP. GMP is sentiment; the prospectus is substance.
- Cross-check the GMP across sources and watch the trend, not a single peak figure. A GMP that is sliding day by day is a warning, not a discount.
- Be extra sceptical of SME GMP. Thin grey markets are the easiest to manipulate. A spectacular SME GMP is a reason for caution, not excitement.
- Anchor to listing-day reality, not peak hype. Decide in advance what you would do if the stock listed flat, because a meaningful share of 2025 IPOs did exactly that.
- Remember GMP says nothing about the long term. Even a correct listing-pop prediction tells you nothing about where the stock trades in a year.
For more on the mechanics, see our companion explainer, what is IPO GMP and how does it work, and track current sentiment on the live IPO GMP page. When you are ready to apply, the IPO allotment checker helps you confirm your application after the issue closes.
Frequently asked questions
Is grey market premium legal in India? Trading in the grey market is informal and unregulated. It is not illegal to read or discuss GMP, but the trades themselves sit outside SEBI's framework, are not legally enforceable, and are not recognised by the exchanges. SEBI has cautioned investors against participating.
How accurate is GMP at predicting listing gains? Studies suggest GMP gets the direction (gain or loss) right roughly 60-70% of the time for large-cap IPOs, and less often for SME issues. It is far less reliable at predicting the exact listing price. In 2025, nearly a third of mainboard IPOs listed below the gains their peak GMP had implied.
Why does GMP change every day? GMP reflects live sentiment in a small, informal market and moves on rumour, subscription numbers, and overall market mood. It often peaks during the subscription window and then falls before listing, which is why anchoring to a peak figure is risky.
Can GMP be manipulated? Yes, particularly for SME and smaller IPOs where the grey market is thin. A few large trades can set a misleading premium, and operators sometimes inflate GMP deliberately to create FOMO among retail investors.
Should I apply for an IPO just because the GMP is high? No. A high GMP reflects current hype, not company quality, and it can collapse before listing. Use GMP only as one input alongside the company's fundamentals, valuation, and the disclosures in its prospectus.
This article is for educational purposes only and does not constitute investment advice. IPO investments are subject to market risks. Please read the offer document carefully and consult a SEBI-registered investment advisor before investing.
Sources: SEBI investor cautions on grey market activity; published analyses of Indian IPO GMP accuracy (2020-2025) and 2025 mainboard listing data. Last reviewed: June 2026 by the ipomarket.in Editorial Team.