Fixed Price and a Book Building Issue in an IPO Explained

When you apply for an IPO in India, you are almost certainly applying through a book building issue. The price band. The cut off price option. The three day subscription window. The QIB, NII, and retail buckets. All of this is the architecture of a book building process. It is so dominant in India today that most retail investors have never knowingly encountered its alternative: the fixed price issue.

Yet understanding the difference between the two is not just academic. It tells you how a share price gets set, who has power over that price, what information is available to you when you apply, and why modern regulators overwhelmingly prefer one approach over the other.

The Simplest Way to Understand the Difference

In a fixed price issue, the company and its bankers decide the share price in advance. You are told the price before the subscription window opens. You apply at that price, pay in full, and wait for allotment. There is no bidding. There is no range. There is one price, and it does not change.

In a book building issue, the company and its bankers do not set a final price before the window opens. They set a price band, a floor and a cap, within which investors are invited to submit bids. Bids from all categories of investors, institutional and retail alike, are collected over the subscription period. The final price is discovered at the point where supply meets demand. The market, in effect, decides what the share is worth.

“In a fixed price issue, the company tells you what the share costs. In a book building issue, you and millions of other investors tell the company what you think it is worth.”

Why Book Building Was Introduced in India

Before 1995, fixed price issues were the only method available for IPOs in India. A company, working with its merchant banker, would set a price and announce it to the public. Investors had no way of knowing whether that price reflected genuine demand or whether it was set too high or too low relative to what the market would support.

The problems with fixed pricing were structural. Companies had every incentive to set prices high to maximise the money raised. If the price was too high, the issue would be undersubscribed and the company would receive less capital than planned. If it was too low, early investors made windfall gains and the company left money on the table. Neither outcome was efficient. There was no mechanism for price discovery and no signal from the market about what investors were actually willing to pay.

In 1995, on the recommendation of the Y H Malegam Committee, SEBI introduced book building as an alternative. The concept had already proven itself in US and European capital markets as a far more efficient way to price new share issues. India adopted it, initially as an option, and over the following two decades it became so dominant that fixed price issues are now rare on the mainboard.

1995 Year SEBI introduced book building in India

20% Maximum spread allowed between floor and cap in a price band

90%+ Share of mainboard IPOs in India using book building today

How a Fixed Price Issue Works

The company and its merchant banker determine the issue price before the IPO opens. This price is based on analysis of the company's financials, its earnings trajectory, the valuations of comparable listed peers, and prevailing market conditions. The price is disclosed in the prospectus, which is filed with SEBI before the subscription window opens.

Once the window is open, investors apply for shares at that single stated price. The full application amount is collected upfront. Investors must pay in advance, and refunds are processed after allotment is finalised. There is no bidding. No price discovery. No option to bid at a higher or lower price.

At least 50 percent of the shares in a fixed price issue must be reserved for retail investors, compared to 35 percent in a standard book building mainboard IPO. The demand for the issue, in terms of total subscriptions at the fixed price, is revealed only after the subscription window closes. There is no live subscription data visible to investors during the process.

Fixed Price Issue: A Worked Example

Company: Hypothetical SME Ltd

Issue Price: ₹120 per share (announced in prospectus before window opens)

Lot Size: 1,000 shares

Minimum Investment: ₹1,20,000 per lot

What the investor experiences:

  Day 1: Window opens. You apply for 1 lot at ₹120. Full amount blocked or paid.

  Day 3: Window closes.

  Day 6: Allotment finalised. Either you get 1,000 shares or you get nothing.

  No bidding. No price range. One price throughout.

How a Book Building Issue Works

In a book building issue, the company and its bankers set a price band rather than a fixed price. SEBI requires that the spread between the floor price and the cap price be no more than 20 percent. So if the floor is set at ₹100, the cap cannot exceed ₹120. This band gives investors the freedom to bid at any price within the range.

Over the subscription period, typically three working days for mainboard IPOs, investors across all categories submit their bids. Retail investors have the option to bid at the cut off price, meaning they agree to pay whatever the final discovered price turns out to be within the band. This is the recommended option for retail applicants because it ensures their application is valid regardless of where the final price falls.

Throughout the subscription window, the live subscription data is published on the BSE and NSE websites. Investors can see in real time how many times the issue has been subscribed across each investor category. This transparency is one of the defining advantages of book building over fixed pricing: the market is telling you, as it happens, how much demand there is for this IPO.

After the window closes, the bankers analyse the book of bids collected across all price points. In an oversubscribed issue, the final price is set at the cut off, which is the price at which the entire issue can be fully subscribed. In almost all popular mainboard IPOs today, the final issue price is set at the upper end of the price band.

Book Building Issue: A Worked Example

Company: Hypothetical Tech Ltd

Price Band: ₹430 to ₹450 per share

Lot Size: 33 shares

Minimum Investment at upper band: 33 × ₹450 = ₹14,850

What the investor experiences:

  Day 1: Window opens. You choose to bid at cut off price for 1 lot.

         Your amount of ₹14,850 is blocked (not debited) via ASBA.

  Day 2: NSE website shows retail category subscribed 12.5 times.

  Day 3: Window closes. QIBs subscribed 68 times. Retail 31 times.

  Final price set at ₹450 (upper end of band, as demand exceeds supply).

  Day 9: Allotment lottery run. Either you get 33 shares or nothing.

         If allotted: ₹14,850 debited. If not: full amount unblocked.

The Price Band and the Cut Off Price

Two concepts sit at the heart of book building and confuse many first time applicants: the price band and the cut off price. They are worth understanding precisely.

The price band is the range within which bids are accepted. The floor is the minimum price at which an investor can bid. The cap is the maximum. SEBI mandates that no price band can have a spread greater than 20 percent between floor and cap. The bankers typically set the floor based on what they believe the issue would comfortably clear, and the cap at what they hope the market will validate through demand.

The cut off price is not a price you enter. It is an instruction you give. When a retail investor selects cut off price on the application form, they are saying: I will accept whatever final price is discovered through the book building process, as long as it is within the band. This is the most sensible option for retail investors because it guarantees your bid is valid at the final price. If you instead bid at a specific price below the final discovered price, your application is rejected.

Why Retail Investors Should Always Bid at Cut Off

If you bid at a specific price, say ₹440 in a ₹430 to ₹450 band, and the final price is discovered at ₹450, your application is treated as invalid. You get no allotment. This happens to thousands of retail investors every IPO season. Bidding at cut off price guarantees your application remains valid regardless of where within the band the final price falls. It costs you nothing extra because the amount blocked is always calculated at the upper end of the band anyway.

Fixed Price vs Book Building: The Complete Comparison

Feature	Fixed Price Issue	Book Building Issue
Price setting	Set by company and merchant banker before the window opens	Discovered through investor bidding within a price band over the subscription period
What investor knows	Exact share price before applying	Price range only. Final price known only after window closes
Investor role in pricing	None. Investors accept the price or do not apply	Investors actively participate. Bids shape the final discovered price
Subscription data	Not available during the subscription period	Published live on BSE and NSE throughout the subscription window
Payment timing	Full amount paid upfront at application	Amount only blocked via ASBA, not debited until allotment is confirmed
Retail bidding option	No bidding. Apply at the stated price	Can bid at cut off price or at a specific price within the band
Retail reservation	At least 50% of shares reserved for retail investors	At least 35% of shares reserved for retail investors (standard route)
QIB participation	Not specifically mandated	QIBs get up to 50% of issue. Their bidding anchors the price discovery process
Price band rule	Not applicable	Floor to cap spread cannot exceed 20% under SEBI rules
Where it is used today	Primarily SME IPOs on BSE SME and NSE Emerge platforms	Almost all mainboard IPOs and most large SME IPOs use book building
Oversubscription signal	Only known after the window closes	Visible in real time throughout the subscription period
Risk to investor	Paying at a price that the market may not support post listing	Risk of bidding below the final price if not using cut off option

Which Method Produces a Fairer Price?

Book building is widely regarded as the superior method for price discovery, and the evidence from two decades of Indian IPO data broadly supports this. When demand from institutional investors and retail participants collectively shapes the final price, it reflects genuine market sentiment at that moment in time. The final price is not the opinion of one company and its banker. It is the aggregate of thousands of bids from investors who have done their own analysis.

Fixed price issues, by contrast, are inherently more speculative on both sides. The company may price too high and see the issue fail, or price too low and leave money on the table. Investors, knowing the price in advance, cannot gauge how the rest of the market views it until after the window closes. There is no live feedback loop.

That said, fixed price issues have a genuine advantage in one important dimension: simplicity. There is no bid entry, no cut off price concept to understand, and no price band to interpret.

For a small company with a narrow investor base and a straightforward offering, the fixed price method can be entirely appropriate. This is why it remains the dominant method in the SME segment, where the issuer size and investor profile are both more suited to a simple, transparent fixed price.

From July 1, 2025, SEBI revised SME IPO rules significantly. Cut off price bidding is no longer permitted for individual investors in SME IPOs, a significant structural shift. All SME IPO applications from individual investors now require a specific price bid within the band, and the minimum application has been raised to above ₹2 lakh. This change makes SME IPOs more demanding for retail participants and is another reason to fully understand the mechanics before applying.

What This Means for You When You Apply

Most mainboard IPOs you encounter today will be book building issues. The practical implications for you as a retail investor are as follows.

You will see a price band, not a fixed price, when the IPO is announced. The minimum investment shown is always calculated at the upper end of the price band, because that is the amount that will be blocked in your account when you apply. You will bid at cut off price in virtually all cases, which means you are automatically committing to the final discovered price.

You can monitor live subscription data on BSE and NSE throughout the three day window, which gives you a real time view of how institutional and retail demand is building.

When you encounter a fixed price issue, the experience is different. You will see a single stated price in the prospectus. There is no subscription data to monitor during the window. You pay the full amount upfront and wait for allotment. Fixed price issues in India today are almost exclusively SME IPOs, so if you see one on a platform like NSE Emerge or BSE SME, that is the context in which you are operating.

The most important practical implication for retail investors is the allotment mechanics. In a book building mainboard IPO, the retail category uses a lottery if oversubscribed, and every winner gets exactly one lot regardless of how many they applied for.

In a fixed price issue, allotment is typically proportionate: if the issue is oversubscribed three times, you receive roughly one third of what you applied for. This means the strategy of applying for the minimum lot in a book building issue does not necessarily carry over to a fixed price issue, where applying for more can result in a larger allotment.

The Hybrid Method: Partial Book Building

SEBI also permits a hybrid approach called a partial book building issue, where a portion of the offering is sold through book building to institutional investors while the remaining portion is offered at a fixed price to retail investors. This structure is less common today but was more prevalent in the early years after book building was introduced in India. It was designed to give institutional investors the benefit of price discovery while keeping the retail application process simple. In practice, the dominance of full book building has made this hybrid structure largely obsolete.

The difference between a fixed price issue and a book building issue is ultimately a difference in philosophy about how a fair share price should be determined. Fixed pricing says the company knows best. Book building says the market knows best. Three decades of global evidence, and India's own experience since 1995, have come down decisively on the side of the market.

For retail investors, the practical takeaway is straightforward. In the book building issues you encounter every week on mainboard platforms, always bid at cut off price. Monitor the live subscription data on BSE and NSE to gauge demand.

Understand that the final price will almost always be set at the upper end of the band in oversubscribed issues. And if you encounter a fixed price issue in the SME segment, recognise that the allotment mechanics are different and that proportionate rather than lottery based allotment means applying for more lots can genuinely improve what you receive.