How accurate is IPO GMP? Why listing differs from GMP

Updated 26 October 2026 · 5 min read

IPO GMP is sometimes close to the actual listing price and sometimes far off. There is no fixed accuracy, because the grey market premium is an unofficial quote from a small group of traders, while the listing price is discovered by the exchange in a pre-open auction with real buy and sell orders. The two are linked by sentiment, but nothing forces them to match.

The honest way to answer "how accurate is GMP" is to look at the record: what the GMP said just before listing, and what the share actually listed at, IPO by IPO. This guide explains why the two differ, what tends to widen or narrow the gap, and how to use the GMP accuracy page on this site to judge for yourself.

Two different prices

The listing price is the equilibrium price found in the pre-open session, where buyers and sellers place orders and the exchange finds the price at which the most shares can change hands. GMP is only an attempt to guess that price in advance.

Why last-day GMP and the listing price differ

• Market mood can change overnight. A sharp fall or rise in the wider market on listing morning affects how many people want to buy or sell.
• Supply on listing day is real. Every allotted investor who wants to sell can place an order in the pre-open session, which can be far more selling than the grey market expected.
• Thin grey market trading. A quote based on a few deals may not reflect what thousands of buyers and sellers do on the exchange.
• Possible manipulation. Because nothing is recorded, a quote can be pushed up or down by a handful of players.
• Different trackers, different numbers. If the sources disagree, any single GMP figure carries extra uncertainty.

What tends to affect the gap

Without claiming any rule, these are the conditions under which investors generally see bigger surprises:

• Very high or very low subscription, where sentiment is stretched in one direction.
• Large swings in the Nifty or Sensex between the issue closing and listing.
• SME IPOs, which are smaller, less liquid and have tighter listing day price bands, so prices can behave differently from mainboard issues.
• IPOs with few sources quoting GMP, or a wide range between sources.
• A GMP that moved a lot in the last day or two, rather than staying steady.

How the GMP accuracy page works

The GMP accuracy page on this site keeps a record of past mainboard and SME IPOs. For each one it shows:

• GMP said: the listing gain implied by the last GMP recorded before the listing day pre-open session. The GMP used is the median of the public trackers the site follows.
• Listed at: the actual listing price against the issue price, and the listing gain in percent. This is the price discovered in the pre-open session, not the closing price of the day.
• Gap: the actual listing gain minus the GMP-implied gain, in percentage points. A small gap means GMP came close; a large negative gap means the share listed below what GMP suggested.

The page also summarises the record: how often the listing came within 5 percentage points of the GMP, the average gap, and how often shares listed below or above what GMP suggested. You can filter by All, Mainboard or SME, which matters because the two boards can behave quite differently. The figures update automatically as new IPOs list, so they reflect the record at the time you look rather than a fixed claim.

A worked example of the gap

Say an IPO has an upper price band of ₹200, and the last GMP before listing is ₹40. The GMP-implied listing gain is ₹40 ÷ ₹200 = 20%. On listing day the pre-open session discovers a price of ₹222, a listing gain of 11%. The gap is 11 − 20 = minus 9 percentage points: the share listed below what GMP suggested. If it had listed at ₹236, the gain would be 18% and the gap minus 2 points, close to the GMP.

How to use GMP sensibly

1. Treat GMP as one view of sentiment, never as a forecast of your profit.
2. Look at the trend and the spread between sources, not one number. Each IPO page here shows the median, the number of sources and a trend chart.
3. Check the accuracy record for the board you are looking at, mainboard or SME.
4. Remember that the listing price is only the opening. The share can move a lot during the rest of the day and afterwards.
5. Base any decision on the RHP, the business and your own goals.

Common mistakes

• Applying only because of a high GMP, without reading anything about the company.
• Borrowing to apply in the hope of a GMP-sized gain.
• Assuming the GMP on day one of bidding will still hold on listing day.
• Comparing GMP with the day's closing price instead of the listing price, which mixes two different things.