Book Building

Imagine an art auction where, instead of the seller simply declaring a fixed price and hoping enough buyers agree, the auctioneer instead collects bids from many interested buyers across a range, then sets the final sale price based on where genuine demand actually clustered. Book building brings almost exactly this price-discovery logic to how most large Indian IPOs are actually priced.

Under book building, a company and its investment bankers set a price band, a lower and upper price limit, rather than one single fixed price, and invite investors to bid for shares at any price within that band, or simply at the cut-off price. As bids come in across the offering period, the company and bankers can see in real time how demand is distributed across the price band, whether investors are clustering their bids near the top, the bottom, or somewhere in between.

The final issue price is then set based on this observed demand, typically at or near the level where the offering is comfortably subscribed, which is why the eventual IPO price frequently ends up at the upper end of the announced band when investor demand is strong, and can be set lower, or the offering can even be pulled entirely, if demand proves weak across the band.

This process typically includes a dedicated Anchor Investor component, where a subset of large institutional investors commit to buying shares at a fixed price a day or two before the public offering opens, both providing an early demand signal to the wider market and giving the company some committed capital locked in ahead of the broader, more uncertain public bidding process.

Whenever an IPO is reported as being priced "at the top of the band" following a heavily oversubscribed offering, that outcome is book building doing exactly what it is designed to do, letting genuine investor demand, not a single guessed number set in advance, determine where the company's shares actually get priced for the public market debut.