This article is an educational explainer about how a common capital markets mechanism generally functions. It does not describe a specific current event, company, or security, and nothing in it should be read as investment advice.
Long before a company’s shares begin trading on the Johannesburg Stock Exchange, the number that eventually flashes on screens on listing day has usually already been shaped by a process that happens almost entirely out of public view. That process is called bookbuilding, and it exists because nobody, not even the company going public or the banks advising it, can know with certainty what the market will pay for a brand-new stock. Understanding how bookbuilding works explains why an IPO’s price can shift within a stated range right up until the night before listing, and why the number first floated to the market is rarely the number it settles on.
Setting the Indicative Price Range
The process begins months before listing, when the company and its appointed underwriters, typically investment banks acting as bookrunners, work through a valuation exercise. They look at comparable listed companies, the business’s financial history, growth prospects, and broader market conditions to arrive not at a single price, but at a range. This indicative range is deliberately wide enough to allow for negotiation but narrow enough to signal that real analytical work sits behind it. It is published in a pre-listing statement or prospectus, the regulatory document lodged in line with Johannesburg Stock Exchange listing requirements and South Africa’s Companies Act, which also sets out the number of shares on offer and the intended use of proceeds.
At this stage, the range is a starting hypothesis, not a conclusion. Bookrunners know from experience that the eventual price depends far less on their internal models than on how real money responds once the offer is actually put in front of buyers. That is the entire purpose of the next stage.
The Roadshow and Early Investor Feedback
With a range in hand, the company’s management team, usually accompanied by the bookrunners, embarks on a roadshow: a series of presentations and one-on-one meetings with fund managers, pension funds, insurers, and other institutional investors, both domestically and often offshore. These sessions allow management to explain the business directly and allow investors to ask pointed questions about strategy, competition, and risk that a written prospectus cannot fully anticipate.
Crucially, the roadshow is also a listening exercise for the underwriters. As meetings progress, bookrunners informally gauge how receptive investors are to the proposed valuation, which becomes an early signal of where genuine demand sits within, above, or below the indicative range. This feedback loop is why roadshows typically run for one to two weeks: long enough to canvass a representative slice of the institutional market, short enough to avoid the offer growing stale or exposed to sudden shifts in broader market sentiment.
Aggregating Demand and Fixing the Final Price
Once the roadshow concludes, the formal bookbuilding period opens. Institutional investors submit orders specifying both how many shares they want and, often, the price or price range at which they are willing to buy, a bid structure known as a limit order within the book. The bookrunners compile every order into a single ledger, the “book,” which shows in real time how demand is distributed across different price levels and how many times the offer is covered by total bids relative to shares available.
This aggregated picture is what ultimately determines the final offer price. If demand clusters heavily near the top of the indicative range or the book is many times oversubscribed, the price is typically set at or above the upper end. If demand is thin or concentrated at lower levels, the underwriters may price nearer the bottom of the range, or in some cases adjust the range itself before finalising. The goal, at least in principle, is a price that clears the market: high enough to raise the intended capital and reward existing shareholders selling down their stake, but calibrated enough that shares still trade in a reasonably orderly fashion once listed. Retail investors, where a retail offer exists alongside the institutional bookbuild, typically pay this same finally determined price rather than negotiating separately. Once fixed, the price is announced, allocations are confirmed, and trading begins, closing a process that started with a wide estimate and ended with a number tested directly against the capital that institutional investors were actually prepared to commit.
