If you follow IPO grey market discussions in India, you will encounter two numbers: GMP and kostak. Most investors understand GMP. Kostak is less well-known but equally important for anyone who participates in grey market activity. This guide explains what kostak is, how it differs from GMP, who pays it and why, and what the risks are.
What Is Kostak Rate?
Kostak (also spelled 'kostak') is the price paid in the grey market for an IPO application — not for the shares themselves, but for the application slot. A buyer in the grey market pays a kostak amount to an applicant in exchange for the right to benefit from whatever shares that application receives.
Example: Imagine an IPO where the grey market kostak is ₹1,500 per application. A grey market operator approaches you and offers ₹1,500 to 'buy' your application. You accept. If you subsequently receive allotment of 1 lot, the operator benefits from those shares at listing. If you receive no allotment, the operator still paid you ₹1,500 — and gets nothing in return.
From your perspective as the applicant, you receive ₹1,500 regardless of whether you get allotment. This is the core appeal of kostak: it converts uncertain allotment outcome into a guaranteed payout.
Kostak vs GMP: The Key Difference
GMP (Grey Market Premium) is the price premium at which IPO shares trade in the grey market before listing. It is expressed per share and represents what someone will pay above the issue price for a share before it lists officially. GMP can be positive (expected listing gain) or negative (expected listing loss).
Kostak is expressed per application (per lot). It is paid before allotment is determined, so it is independent of whether the applicant gets shares.
- GMP example: IPO issue price ₹500, GMP ₹80 → grey market expects listing at ₹580
- Kostak example: Kostak ₹2,000 per application → a buyer pays ₹2,000 for your entire application regardless of allotment outcome
If the lot size is 60 shares and GMP is ₹80, the 'expected value' per allotted lot is 60 × ₹80 = ₹4,800. A kostak of ₹2,000 would be attractive to the buyer if they believe allotment odds are above roughly 42% (₹2,000 / ₹4,800). It would be attractive to the seller if they want to lock in ₹2,000 rather than risk getting nothing.
Why Does Kostak Exist?
Kostak exists because demand for IPO shares sometimes vastly exceeds the supply of applications. In highly oversubscribed IPOs, allotment odds for retail investors can be as low as 1 in 80 or 1 in 100. Grey market operators who want exposure to the IPO but cannot apply for more shares (one PAN = one application in retail) are willing to pay for access to other applicants' slots.
From the operator's perspective, buying 100 applications at ₹2,000 kostak each (₹2,00,000 total) and expecting 1–2 allotments (worth ₹4,000–₹8,000 per lot at listing GMP) may not seem profitable — unless they are purchasing hundreds or thousands of applications. At scale, the math can work.
The practice is most common for high-demand mainboard IPOs where allotment lottery odds are low and listing premiums are expected to be large.
Is Kostak Legal?
No. Kostak transactions are not regulated or recognised by SEBI. Trading IPO applications — or the shares expected from them — before official listing is a violation of SEBI regulations on grey market activity. Neither SEBI nor the exchanges endorse, monitor, or protect participants in grey market transactions.
This means:
- If the operator fails to pay you after you transfer allotted shares, you have no legal recourse
- If you transfer shares to the operator and they default, your broker cannot help you recover them
- SEBI can theoretically take action against participants in grey market transactions, though enforcement against individual retail investors is rare
Kostak and grey market transactions exist in a legal grey area — informal, unregulated, and entirely at the participant's own risk.
The Risks of Accepting Kostak
Even setting aside the legal question, accepting kostak carries practical risks:
- Capital lock-up: Your application money remains blocked in your bank account for the full subscription period (typically 6–8 days) whether or not you accepted kostak. You cannot use those funds for other purposes during this time.
- Counterparty risk: Grey market operators are informal — there is no contract. If they disappear or refuse to pay after allotment, you have no enforceable claim.
- Tax complexity: Any income from grey market transactions is taxable. The income may be treated as 'income from other sources' or business income, depending on frequency and scale. Most grey market participants do not report this income.
- Broker friction: Some brokers flag accounts involved in unusual share transfer patterns around IPO listing dates.
What a High Kostak Signals
Kostak is a grey market indicator, similar to GMP. A high kostak relative to the expected allotment value signals strong grey market demand for the IPO — operators are paying a lot per application because they expect high listing gains.
Like GMP, kostak is an informal indicator with no regulatory basis. It reflects grey market sentiment, not fundamental value, and can be influenced by the same operators who are buying applications. Treat it as one data point among many — not a guarantee of listing price.
Related Reading
- What Is IPO GMP? A Complete Grey Market Premium Guide — understand GMP before you interpret kostak
- Negative GMP in IPO: What It Means and Should You Still Apply? — negative GMP also suppresses kostak rates
- How to Check IPO Allotment Status — allotment is the event that determines whether a kostak buyer gains or loses
Disclaimer
This article describes grey market practices for informational purposes only. IPOLyst does not endorse, facilitate, or recommend participation in grey market transactions. Grey market activity is unregulated and carries significant legal and financial risk. IPOLyst is not a SEBI-registered investment advisor. Please conduct your own research before investing.