IPO GMP (Grey Market Premium), Explained
GMP is the number every IPO investor watches — but it is widely misunderstood. Here is what it actually means, and how to read it sensibly.
What is the grey market?
The grey market is an unofficial, over-the-counter market where IPO shares (and applications) are bought and sold before they officially list on the stock exchange. It is not regulated by SEBI or the exchanges, operates on trust between a handful of dealers, and settles privately. Because it is unofficial, there is no central price, no guarantee, and no legal recourse.
What is GMP?
The Grey Market Premium (GMP) is the extra amount, over and above the IPO issue price, that buyers in the grey market are willing to pay for a share before listing. For example, if an IPO’s upper price band is ₹100 and the GMP is ₹30, grey-market buyers are paying roughly ₹130 — implying the market expects the stock to list around that level.
Two other grey-market terms you’ll hear
- Kostak — a fixed amount paid to buy someone’s entire IPO application (regardless of whether it gets allotment).
- Subject-to-Sauda (STS) — a deal to buy an application that is honoured only if shares are actually allotted.
How to read GMP sensibly
- It is a sentiment gauge, not a forecast. A high GMP signals strong demand and optimism; it does not guarantee a strong listing.
- It is volatile. GMP can swing sharply in the days before listing as demand, subscription figures and market mood change.
- It can be manipulated. Because volumes are thin and the market is unofficial, a small number of trades (or rumours) can move the quoted GMP.
- Pair it with fundamentals. Subscription numbers, the company’s financials, valuation and the overall market matter far more for a long-term decision.
Why you should be cautious
GMP is unofficial and unregulated. Many IPOs with a high GMP have listed flat or at a loss, and vice-versa. Treat GMP as one small, noisy data point — never as a reason on its own to apply. Read the prospectus, understand the business, and decide based on your own goals and risk appetite.
Where does the GMP number actually come from?
There is no exchange, ticker or official feed for GMP. It is a word-of-mouth price quoted by a small network of grey-market dealers concentrated in a few trading hubs, then passed along to websites and messaging groups that republish it. Different sources can show slightly different numbers on the same day because each samples a different set of dealers. That is exactly why you should treat any single GMP figure as an approximation, not a quote you can rely on.
A worked example
Say an IPO has a price band of ₹95–₹100 and a lot size of 150 shares, and the GMP is ₹40:
- Implied listing price ≈ ₹100 + ₹40 = ₹140
- Implied listing gain ≈ 40 ÷ 100 = 40%
- On one lot (150 shares) that is a notional first-day profit of about ₹6,000 — if the stock lists at the implied price, which is never guaranteed.
Note the gain is measured against the upper band (the price you almost always pay via the cut-off option). Always convert GMP to a percentage: a ₹40 GMP means something very different on a ₹100 issue than on a ₹2,000 issue.
Read GMP together with subscription
GMP on its own is noisy. It becomes far more useful next to the live subscription figures. A high GMP and heavy QIB/NII demand tells a more consistent story than a high GMP with weak institutional interest — the latter can mean the grey market is running ahead of real conviction.
When GMP misleads
- Last-day spikes. GMP often jumps in the final day or two as hype builds, then deflates once listing arrives.
- Thin, illiquid quotes. Because volumes are tiny, a few trades or one rumour can move the published number.
- Market gaps. A weak broader market on listing day can turn a healthy GMP into a flat or negative listing regardless of the night-before number.
Frequently asked questions
Is trading in the grey market legal?
Grey-market deals are unofficial and unregulated — settled privately on trust, with no exchange protection and no legal recourse if a counterparty defaults. Ordinary retail investors never need to touch it; you simply apply through the normal ASBA/UPI route.
Does a high GMP guarantee a strong listing?
No. Many high-GMP IPOs have listed flat or below issue price, and some low-GMP issues have surprised on the upside. GMP is a sentiment gauge, not a forecast.
Should GMP decide whether I apply?
Use it only as one small, late-stage input. The business, valuation and your own goals should drive the decision — start with our guide to reading a DRHP.