What is Kostak in IPO?
Kostak in IPO refers to the fixed price or premium at which IPO applications are bought and sold in India’s grey market, independently from the final share allotment outcome.
This is an informal arrangement, allowing original IPO applicants to earn a guaranteed profit by selling their right to apply, transferring the risk and potential rewards to the buyer.

How does Kostak Work in IPO Applications?
Kostak rate exclusively applied to the value of an entire IPO application, typically per retail lot, with deals occurring before share allotments announced.
- If an IPO oversubscribed, selling at Kostak allows investors to book a certain profit regardless of allotment.
- The buyer pays the Kostak premium, and takes the chance based on the share allotment process, which ultimately determines whether shares received.
- Both parties agree to the deal based on current market sentiment, demand, and projected listing gains.
Comparison: Kostak Rate vs GMP and Sauda
| Term | Definition | Risk Profile | When Used |
|---|---|---|---|
| Kostak Rate | Fixed premium for full IPO application | Low (guaranteed for seller) | Before allotment |
| GMP (Premium) | Premium per share listed | High (depends on listing) | Predicting listing price. See examples of listing gains from grey market trades for real-world illustrations |
| Subject-to-Sauda | Premium paid only if allotment occurs | Medium | On allotment confirmation |
Legality and Risks of Kostak Trading
Kostak not regulated by SEBI, considered unofficial, and exposes participants to legal ambiguity and counterparty risk.
Transactions rely on trust and carry the risk of default, overvaluation, and loss if the IPO does not perform as expected or the agreement is breached.
For further reading, users can explore more on the risks associated with grey market activities and how these can impact investors.
How Kostak Rate Decided?
Kostak rates determined by market excitement, expected listing gains, oversubscription levels, and overall grey market premium trends that reflect real-time investor sentiment..
- High demand for an IPO can push up the Kostak rate.
- Historical trends and grey market sentiment guides the negotiation between sellers and buyers.
Benefits and Drawbacks for IPO Investors
- Benefits: Kostak rates provide liquidity, certainty of profit, and bypass waiting for allotment confirmation.
- Drawbacks: Unofficial nature exposes sellers and buyers to reliability issues and legal risk, making it a high-risk, informal transaction.
How to Check Kostak Rate of Upcoming IPOs
Financial portals and grey market tracking websites publish daily Kostak rates for new IPOs to help investors gauge application value and market optimism.
In the context of grey market trades, being aware of the difference between IPO GMP and official listing price is crucial to set realistic expectations.
Conclusion:
Understanding Kostak in IPO helps investors make strategic decisions, weighing guaranteed profits against risks and legality in the IPO grey market. It remains a key indicator of IPO demand and an alternate route for profit even before allotment and listing in IPOs with high oversubscription.










