This article is educational content explaining how a general market mechanism works; it is not investment advice and does not describe a specific current event, company, or security.
When a company decides to list its shares on the Nigerian Exchange (NGX), one of the earliest decisions its advisers make barely gets a headline, yet it determines whether every investor in the offer pays an identical, pre-set price or whether the eventual price only emerges after days of bidding across a range. That choice, between a fixed price offer and a book building process, shapes how demand is measured, how shares are allotted, and how closely the initial market price reflects what investors were actually willing to pay.
Two Ways to Bring Shares to Market
In a fixed price offer, the issuing house, usually an investment bank or stockbroking firm acting as financial adviser, works with the company to set a single subscription price before the offer opens. That price is fixed using valuation methods such as discounted cash flow analysis, comparable company multiples, and the company’s own financial projections, then published in the prospectus. Investors simply decide how many shares they want at that price; there is no bidding involved. This method is simple and predictable and has historically been common for smaller or first time issuers on the Nigerian market, since it is easier to explain to retail investors and less dependent on active institutional participation.
Book building, by contrast, does not fix a single price up front. Instead, the issuing house and the appointed underwriters publish a price range, a floor and a ceiling, and invite investors to submit bids specifying both the price they are willing to pay within that range and the number of shares they want at that price. The final price is only determined after the bidding window closes, based on how demand is distributed across the range.
How the Book Is Built
During the offer period, the issuing house and underwriters, often referred to collectively as bookrunners, collect bids from a mix of institutional and retail investors through participating stockbrokers. Each bid is recorded in an order book, a running tally of how many shares are demanded at every price point within the range. As bids arrive, a picture of the demand curve emerges: some investors bid near the floor, expecting a lower clearing price, while others, more confident in the offer’s appeal, bid closer to the ceiling to improve their chances of receiving an allotment.
Underwriters play a dual role in this process. They advise on where to set the initial price range based on investor feedback gathered before the offer even opens, a step often called pre-marketing, and they commit, subject to the terms of the offer, to help ensure the issue is fully subscribed. Their read on institutional appetite is one of the key inputs behind whether the eventual range is set realistically.
Turning Bids Into a Price and an Allotment
Once the bidding window closes, the issuing house aggregates every bid into a cumulative demand schedule and identifies the price at which total demand is just sufficient to absorb the total number of shares on offer. This is often called the clearing price or cut off price. Bids placed below the clearing price are typically excluded from allotment, while bids at or above it are considered.
Allotment itself is a separate mechanical step from pricing. Because a book built offer is frequently oversubscribed at the clearing price, the issuing house applies an allotment methodology, disclosed in advance in the prospectus, that may involve proportional scaling down of larger bids, minimum guaranteed allotments for retail investors, or a mix of both, all subject to rules set by the Securities and Exchange Commission and the NGX’s listing requirements. The outcome is that every successful investor pays the same clearing price, regardless of whether their own bid sat at the floor, the ceiling, or somewhere in between, which is why book building is often described as producing a market discovered price rather than an administratively fixed one.
