Indian Mainboard IPOs: GMP Gets Direction Right, Not Magnitude

Indian mainboard initial public offerings show that the final grey market premium was a useful directional indicator in 2026, but not a precise forecast. In a 109-IPO tracker, GMP and listing gains had a 0.91 correlation, while 80% of mainboard IPOs landed within 10 percentage points of the implied gain.

How accurate was GMP for mainboard IPOs in 2026?

GMP was directionally useful for mainboard IPOs, although its accuracy varied depending on the dataset and measurement period. The broadest tracker covered 109 mainboard IPOs listed through 28 October 2026 and found a 0.91 correlation between GMP percentage and listing gain percentage. It recorded an average miss of 7.0 percentage points, with 58% of issues within 5 points and 80% within 10 points of GMP.

A smaller 51-IPO mainboard sample produced a similar directional result. GMP was on the right side of the issue price in 41 cases, or 80%, and was within 10 points of the actual opening gain in 35 cases, or 69%. Its median miss was 5 points, showing that the typical difference can be manageable even when some individual outcomes differ substantially.

What do the latest mainboard IPO listings show?

The most recent named mainboard IPOs show both close GMP calls and a sizeable miss. Jio Platforms Limited opened at ₹1,358 against an issue price of ₹1,119, a 21.36% gain that was close to its final GMP estimate of 22.34%. Paras Healthcare Limited opened 3.90% above its ₹693 issue price, compared with a final GMP indication of 1.59%.

Sahajanand Medical Technologies Limited also opened near the final GMP signal, gaining 7.89% versus a 6.98% estimate. Bonfiglioli Transmissions Limited illustrates the limitation of relying on GMP as a price target: its final GMP implied a 21.67% premium, but it opened at its issue price of ₹586. The supplied recent-listings table contains four named issues despite referring to five most recent IPOs, so no fifth company has been added.

Why do GMP results differ across IPO trackers?

GMP results differ because the trackers use different samples, dates and, in some cases, different listing-day measurement points. One 70-IPO sample found that GMP got the direction right 55 times, or 79%, and was within 10 percentage points of the actual opening gain in 60% of cases. Another 104-IPO comparison found that 70% of IPOs with a positive GMP listed above their issue price and reported a median gap of 7.8 percentage points.

The direction of the error is not consistently one-sided. A 35-mainboard-IPO study for listings between 3 September and 8 October found GMP was too optimistic in 18 cases and too pessimistic in 17 cases, with an average gap of 12.5 percentage points. Separately, a 104-IPO comparison found average GMP-implied gains of 21.8%, against average actual gains of 18.8%, and a median IPO listed 3.2 points below GMP.

Is GMP more reliable for mainboard IPOs than SME IPOs?

The reported data indicates that GMP has generally been more reliable for mainboard IPOs than SME IPOs. In the 109-mainboard-IPO tracker, the average miss was 7.0 points and 80% of issues were within 10 points. The same tracker reported a 9.6-point average miss for SME IPOs and 63% within 10 points.

A separate 104-IPO study reached the same broad conclusion but with different absolute figures. It found that 71.2% of mainboard IPOs were within 10 points of GMP, compared with 36.8% of SME IPOs, while the respective median gaps were 6.1 and 16.2 points. These comparisons support using GMP as one data point for mainboard issues, not as a stand-alone estimate of the opening price. The grey market is unregulated, and correlation does not guarantee an outcome for an individual stock.

Conclusion

The 2026 record suggests that final GMP has been a reasonably strong signal of whether a mainboard IPO may list above or below its issue price. The evidence is less supportive when GMP is treated as an exact estimate of the opening gain: even the larger 109-IPO tracker recorded an average miss of 7 percentage points, and recent outcomes ranged from close matches to Bonfiglioli Transmissions Limited opening flat despite a positive GMP.

Investors should watch the final GMP only alongside the issue price and the eventual exchange-recorded listing price, while noting which tracker’s sample and measurement point are being cited. The next test will come from upcoming listings, including open mainboard issue M.K.Sons Fine Jewels Limited, whose GMP was recorded at +6% as of 30 October 2026.