IPO Bookbuilding and Allocation

A company going public has no market price yet — there's no history of trades to look at. So how does anyone decide whether the stock should be offered at $18 or $24 a share? The underwriters don't guess; they ask. Over roughly one to two weeks, they run a roadshow, pitch the company to institutional investors, and collect actual orders at actual prices. That process of collecting demand before setting a price is bookbuilding, and the resulting order book is what the final price and, separately, who receives stock, both come out of.

Building the book

The underwriters (the investment banks running the deal) set an initial price range, say $18–$21, based on comparable company valuations. During the roadshow, institutional investors — mutual funds, hedge funds, pension funds — submit indications of interest: how many shares they want, and at what price they're willing to pay, sometimes as a limit ("I'll take 500,000 shares up to $20") and sometimes at the market ("I'll take whatever the final price is"). The lead underwriter aggregates every order into a single book, tracked in real time, showing total demand at each price point in the range and above it.

This is deliberately not a sealed auction. The underwriter can see the whole book as it forms and talk to investors throughout, adjusting the price range up if the book fills quickly (a sign of strong demand) or pulling the deal if it doesn't fill at all. That visibility and control is the entire point of bookbuilding over a pure auction — it lets the underwriter calibrate price to real demand rather than hope an auction clears somewhere sensible.

Setting the price and allocating stock

Once the roadshow ends, the underwriter and the company jointly pick a final offer price — deliberately set a notch below where the book suggests the stock would trade, most of the time. That gap is intentional: it leaves a first-day pop for investors who received an allocation, which rewards the institutions that did the work of researching and honestly indicating demand, and gives the deal a visibly "successful" debut. The average first-day return across US IPOs has historically run in the high single digits to double digits — money left on the table by the company, deliberately, to keep the process working smoothly for next time.

Not everyone who submits an order gets filled. Allocation is the underwriter's discretionary decision about who receives how much stock, and it heavily favors large, long-term institutional investors who are seen as more likely to hold the stock (supporting the price after listing) over short-term "flippers" likely to sell on day one. A hedge fund known for quick profit-taking might submit a $50 million order and receive only a token allocation; a large mutual fund with a long-only reputation might get a much larger share of a smaller order.

A worked example

A company offers 10 million shares in a $18–$21 range. By the end of the roadshow, the book shows: at $18, orders for 35 million shares; at $19.50, orders for 22 million shares; at $21, orders for 9 million shares. The deal is oversubscribed at every price up to $19.50 — demand at that price (22 million) is more than double the 10 million shares on offer. The underwriters set the final price at $19.50, in the upper half of the range but not at the very top, and allocate the 10 million shares mostly to the large, long-term investors who bid at or above that price.

Suppose the stock opens for trading the next day at $23. Investors who received their full allocation see an instant 17.9% first-day return, computed as $(23 - 19.50)/19.50$. A hedge fund that asked for 2 million shares but was allocated only 200,000 made a smaller dollar profit than it wanted, but still profited; an investor who tried to buy on the open market on day one paid $23 and got none of that pop.

• Retail investors almost never get an IPO allocation at the offer price through ordinary brokerage accounts — allocations go overwhelmingly to institutions with existing underwriter relationships.
• The lock-up period, typically 90–180 days, prevents company insiders and early investors from selling — watch for a second price move when it expires and a wave of new supply hits the market.
• A deal that prices below the range, or is pulled entirely, is the clearest signal the book didn't fill — treat range cuts as a real demand signal, not a rounding choice.