What it means
When a company decides to go public or issue new shares, it needs to find out what buyers are willing to pay. Instead of guessing a fixed price, the company sets a price range and invites large investors, such as pension funds and asset managers, to submit bids indicating how many shares they want and at what price within that range.
This collection of bids forms a 'book'. The lead bank manages this process over a period of usually one to two weeks, adjusting the price guidance based on demand.
If demand is exceptionally high, the final price is set near the top of the range. If interest is lukewarm, the price may be lowered to ensure all shares find a buyer.
This matters because pricing a share issue incorrectly can damage a company. If priced too high, shares go unsold and the launch fails.
If priced too low, the company leaves money on the table that could have funded growth. Bookbuilding uses market feedback to discover the fair value.
In practice, investment bankers use these indications of interest to allocate shares fairly among institutional buyers. They often favour long-term investors over short-term traders to create a stable post-launch market.
Once the final price is locked in, the shares are officially priced and allocated. Bookbuilding is like a silent auction for a rare painting where registered bidders submit their best offers in secret.
The organiser reviews all the bids to find the highest price at which every available painting will be successfully sold.
In practice
Real-world examples
Example 1
TechStart UK plans to float on the stock exchange. Through bookbuilding, institutional investors bid for five million shares. Strong demand pushes the final price to $2.50 per share, raising $12.5 million for the software firm. The founders note that every extra 10 cents on the price would have added $500,000.
Example 2
GreenEnergy Ltd wants to raise capital for a new factory. During bookbuilding, the investment bank notices weak demand at $4.00, so they adjust the price down to $3.50, successfully selling all 2 million shares and securing $7 million. Had they held at $4.00, the issue risked being left unsold.
Example 3
A mature logistics firm uses bookbuilding for a secondary share offering. Institutional demand is overwhelming, allowing the firm to increase the total number of shares sold while maintaining a stable share price of $5.00. If it sells an extra 1 million shares at that price, it raises a further $5 million without lowering the price.
Think of it
Bookbuilding is like a silent auction for a rare painting where registered bidders submit their best offers in secret. The organiser reviews all the bids to find the highest price at which every available painting will be successfully sold.
Formula
Calculation
Total Capital Raised = Total Shares Sold x Final Issue Price
Example: A company issues 2,000,000 shares and bookbuilding determines a final price of $3.00 per share. The calculation is 2,000,000 x $3.00 = $6,000,000 raised before transaction fees.
Two further checks are useful. Oversubscription = Shares Bid For / Shares Offered, so if investors bid for 5,000,000 shares and only 2,000,000 are on offer, the book is 5,000,000 / 2,000,000 = 2.5 times covered. If underwriting and advisory fees come to 4% of the amount raised, they cost 0.04 x $6,000,000 = $240,000, leaving net proceeds of 6,000,000 - 240,000 = $5,760,000.Case study
Seen in the real world
Brighton BioTech, a fictional medical research company, decided to list on the alternative investment market to fund clinical trials. They appointed an investment bank to run a bookbuilding process with a tentative price range of $1.50 to $2.00 per share, aiming to sell 10 million shares. During the two-week roadshow, institutional investors showed exceptional interest, submitting bids for nearly 25 million shares. Recognising this heavy oversubscription, the lead bank advised Brighton BioTech to price the shares at the top of the range, exactly $2.00. As a result, the firm raised $20 million (10,000,000 x $2.00), which was $5 million more than the $15 million it would have raised at the bottom of the range.
The disciplined bookbuilding process ensured they did not underprice the stock, while careful allocation favoured long-term healthcare funds, leading to a stable and successful market debut the following week. The book was about 2.5 times covered (25 million bids for 10 million shares), so most investors received only part of what they asked for. The bank scaled back allocations and gave priority to long-term holders, which reduced the risk of heavy selling on the first day. Because the company is fictional, these figures are illustrative only, but they show how demand directly shapes both price and allocation.
Watch out
Common mistakes
- Treating bookbuilding as a guarantee of share price performance after listing.
- Setting the initial price range unrealistically high, which deters serious institutional bidders.
- Ignoring market feedback during the roadshow and refusing to adjust the price when demand is low.
Questions
People also ask
Who participates in the bookbuilding process?
Mainly institutional investors such as pension funds, insurance companies, and mutual funds, rather than everyday retail investors.
Can the price range change during bookbuilding?
Yes, investment banks often adjust the price range up or down based on the level of demand received from investors.
What happens if a share offering is oversubscribed?
When demand exceeds the number of shares available, the company and its bankers scale back allocations to each investor to ensure fair distribution.