How a stock exchange works

More than the opening bell

A stock exchange provides a framework in which securities can be admitted and buyers and sellers can trade under defined rules. The trading screen is only part of the process: a matched order still has to reach the institutions that arrange delivery and payment.

For an IPO team, distinguish raising money, obtaining the relevant admissions, forming a trading price and completing delivery. Treating them as one event can leave gaps in the launch plan. This guide explains the mechanisms, not a universal set of listing requirements.

Primary and secondary markets

In the primary market, the company issues new shares to investors. The company receives the proceeds, before transaction costs. In the secondary market, existing shares change hands; the proceeds go to the seller, not to the company.

An IPO can combine new shares with sales by existing shareholders. Those shareholder sales are a secondary component of the offering, distinct from subsequent exchange trading. A busy aftermarket does not itself put new cash on the company's balance sheet.

The corporate-finance question is how much capital the company needs. The market-structure question is how investors will be able to trade afterwards. Work through the distinction with the offer structure calculator; it is not a forecast of trading liquidity.

Listing is not the same as admission to trading

Listing can mean formal inclusion on an official list or admission to a specified listing category. Admission to trading means permission for a security to trade on a particular market. Terminology and the division of responsibilities vary by jurisdiction: do not assume every market uses “listed” in the same legal sense.

In the IPO workstream plan, give each approval its own owner, conditions and effective date. Do not treat prospectus approval, listing approval and trading admission as interchangeable milestones. Confirm which are relevant with the regulator, exchange and advisers for the chosen transaction.

Regulated markets, MTFs and growth segments

Regulated market and multilateral trading facility (MTF) are distinct legal categories in the EU's Markets in Financial Instruments Directive (MiFID II). Both bring together buying and selling interests under non-discretionary rules, but their regulatory frameworks differ. An MTF is not an unregulated market.

An SME growth market is a registered type of MTF under that framework; SME means small and medium-sized enterprise. “Growth” in an exchange's branding is not, by itself, proof of this legal status. Nor does every MTF serve only smaller companies.

The useful comparison is not “strict versus no rules”. Ask which admission document, financial reporting, disclosure, governance and adviser arrangements apply. ESMA's SME growth-market provisions include admission information, periodic reporting and market-abuse safeguards. They are not a blanket exemption from public-market obligations.

A segment name does not establish likely liquidity, investor eligibility or index access. Use the listing venue guide to frame the decision, then verify the current rules of the actual market. This page specifies no admission thresholds, fees or reporting deadlines.

How an order book forms a price

An order book collects buy and sell orders for a security. The bid is a buying price; the ask, or offer, is a selling price. The difference between the best displayed bid and ask is the spread. Depth describes the quantities available at different prices.

A limit order sets a maximum buying price or minimum selling price. It protects the price boundary, not the likelihood of execution. A market order seeks execution at available prices without that boundary; a large order can fill at different prices. The last reported trade is not a guaranteed execution price.

In continuous order-book trading, compatible orders can match as they arrive. The venue's rules decide priority. As a specific illustration, Xetra's published model uses price/time priority: a better price takes precedence, then earlier entry at the same price. Do not generalise that matching rule to every venue or order type.

The exchange's trading order book is also different from an IPO bookrunner's demand book. The latter supports offer pricing and allocation; it is not a queue of guaranteed aftermarket buyers.

IPO implication: ask the banks to distinguish expressed demand, allocated shares and executable trading interest. A headline about oversubscription does not show what depth will remain after trading starts.

Opening and closing auctions

An auction concentrates orders for a price determination rather than matching each compatible order immediately. Eligible buying and selling interests are brought together at a common auction price. The venue defines which orders participate, how the price is selected and how imbalances are handled.

An opening auction helps establish a price before continuous trading. A closing auction concentrates interest at the end of the main session and can establish the official closing price. Xetra's published continuous-trading model uses these mechanisms, with auction pricing based on executable volume and remaining imbalance. Its closing price also serves as a portfolio valuation reference.

An indicative auction price is provisional: orders can change before price determination. The opening price need not equal the IPO offer price. Also distinguish an exchange opening auction from an auction used to sell shares in an offering; they perform different jobs.

IPO implication: agree who coordinates the first trading session and confirms the published opening and closing prices. Use the first-day return calculator only after identifying the correct offer price and market-price observation. It measures a return, not liquidity or investment quality.

Market makers and designated sponsors

A market maker deals using its own capital, standing ready to buy and sell at quoted prices. Its quotes can supply trading interest when investor orders alone do not meet. This is different from simply passing a client's order to the market.

Roles and obligations are venue-specific. On Xetra, Designated Sponsors provide binding buy and sell quotes to support liquidity, including participation in auctions. Check the current rules for the obligations attached to that role. The title should not be assumed to mean the same thing as a similarly named adviser or sponsor elsewhere.

A liquidity provider is not a guarantee of a minimum share price, unlimited buying capacity or permanent investor demand. Do not confuse ordinary quoting with IPO stabilisation, which is a separate activity requiring its own legal and transaction-specific assessment.

IPO implication: ask what service is being contracted, which securities and trading phases it covers, and how performance will be monitored. Do not describe a sponsor appointment as a commitment to support the offer price.

After the match: clearing and settlement

Execution creates the trade. Clearing establishes the obligations to be fulfilled, potentially calculating net positions. Settlement completes the relevant transfers of securities and cash. These are different functions even when providers belong to the same corporate group.

Not every trade follows a CCP-cleared route. Confirm the arrangements for the instrument rather than assuming the same chain applies everywhere.

Delivery versus payment (DvP) links securities delivery to the corresponding cash payment. That reduces the risk of delivering one leg without receiving the other; it does not eliminate every operational or counterparty risk.

The notation T+n means the trade date, T, plus the applicable number of business days, n. It describes the intended settlement timing, not a promise that a trade cannot fail. A trade confirmation is not the same as completed settlement. The relevant cycle, holidays and operational cut-offs depend on the market and transaction; this guide does not prescribe a universal interval. The offering's delivery timetable must also be checked separately from the normal aftermarket cycle.

IPO implication: ask the banks and settlement providers to confirm security identifiers, issuance and custody arrangements, cash funding, delivery instructions and responsibility for resolving failures. Put those confirmations into the launch plan rather than assuming the first matched trade completes the job.

Free float and index inclusion

Free float describes shares available for public trading rather than held in strategic or otherwise excluded holdings. It is not identical to the number of shares sold in the IPO. Exchange and index definitions can treat holdings differently, so use the definition relevant to the test being performed.

Index inclusion is a separate decision under an index provider's methodology, not an automatic consequence of listing. Eligibility, selection and weighting are distinct questions. A methodology may consider free float, size, trading activity, geography, listing characteristics or review timing; there is no universal index-entry checklist.

IPO implication: a tightly held register can leave less stock available for trading. Do not promise index membership or passive buying as part of the equity story. Ask which holdings count as free float, which methodology applies and when eligibility could actually be assessed.

What the IPO team should take away

Use market structure as a set of questions for the launch plan:

• Finance: distinguish company proceeds from shareholder proceeds and confirm the offering's cash-delivery timetable.
• Legal and listing advisers: identify the exact legal market category and each separate approval.
• Banks and trading contacts: explain order handling, the opening process and the scope of liquidity provision.
• Settlement providers: confirm how securities and cash reach the right accounts and who handles exceptions.
• Investor relations: monitor trading conditions without confusing price movements, free float or index eligibility with guaranteed demand.

Carry the operational handover into the first days after listing checklist. The objective is not merely to start trading, but to understand the market in which shareholders will trade.

Official sources and scope

Retrieved 28 October 2026. These official educational and regulatory sources support the concepts and named illustrations above. No exchange-specific fee, numerical admission threshold, auction timetable or current settlement interval is asserted here. Transaction requirements must be checked against the applicable current rules. Educational content only. Not investment advice.