The ASX explained for investors used to other markets

A concentrated market, and why that matters

The most important structural fact about the Australian share market is concentration. A relatively small number of very large companies account for a substantial share of total market value, and the largest of them are banks and resource producers. This is not a temporary condition. It reflects the shape of the Australian economy, and it has consequences for anyone reading index performance or building a diversified holding.

Three consequences are worth stating plainly. First, an index return in Australia is heavily influenced by a handful of companies, so "the market was up" may describe very little about the average listed company. Second, sector diversification is harder to achieve than the number of listed companies suggests, because financials and materials dominate the total. Third, when a widely held index moves, the movement often tells you about banks and iron ore more than about the breadth of Australian business conditions.

For a reader used to the depth and sector spread of the United States market, this is the single adjustment that matters most. The number of listed entities is large; the number that materially drive index outcomes is small.

Who does what: exchange, regulator and clearing

In Australia the roles that are separated in some overseas markets are held by different types of entity, and conflating them causes confusion.

The practical point for a reader: a complaint about a company's disclosure goes to ASIC or to the ASX depending on its nature, and a complaint about a broker's conduct generally goes to ASIC or to the relevant external dispute resolution scheme. Reading a company's announcement on the ASX platform is free and does not require an account.

How companies list, and the small-cap tail

ASX listing rules set out admission requirements and continuing obligations. Companies are grouped by size into indices and, informally, into tiers: large, mid and small caps, with a long tail of very small companies below that.

The tail is worth understanding, because the distribution of company quality in it is wide. Some small companies are serious businesses early in their life. Others have limited revenue, no profits, and a business description that is difficult to test against anything. Disclosure obligations apply to all of them, but the volume and usefulness of what a small company publishes varies enormously, and the depth of independent analysis available on it is often thin.

Two structural features are relevant here. Australia has a substantial resources exploration sector, where companies may have no revenue for years and their principal asset is an exploration tenement whose value depends on technical reports. Australia also has a large number of listed investment vehicles and trusts, whose financial statements look different from those of an operating company and are worth approaching separately. Neither category is inherently problematic; both require the reader to check what kind of entity they are looking at before applying any of the usual measures.

Reporting cadence and continuous disclosure

Australian reporting obligations differ from the United States in a way that surprises many readers.

• Half-yearly, not quarterly. Australian listed companies generally report to the market twice a year: a half-year report and a full-year report. There is no general obligation to publish quarterly financial statements. Readers used to quarterly reporting are looking at a market with roughly half the reporting frequency, which means less frequent updates and a larger information gap between reports.
• Continuous disclosure. Set against that lower frequency is a continuous disclosure obligation. A listed company must immediately tell the market about information it becomes aware of that a reasonable person would expect to have a material effect on the price or value of its securities. This is why material news can arrive at any time as a market announcement rather than waiting for a reporting date.
• Annual reporting content. The annual report includes the financial report, the directors' report with a remuneration report, and an audited set of statements. The content requirements are prescribed, so the structure is broadly consistent across companies even when the businesses are not.
• Climate and sustainability reporting. Australian reporting requirements in this area have been changing, with obligations being phased in for larger entities. Because the requirements depend on the entity and the period, check the current position rather than relying on a description written earlier.

The practical implication is that in the Australian market the announcement feed matters more than it does in a quarterly reporting market. A reader who only reads annual reports will learn about significant events months late.

Trading hours and settlement

The ASX operates a single main trading session on business days, with a pre-open phase before continuous trading begins and a closing auction at the end. Trading in a security is paused when the company releases market-sensitive information, so that the information reaches everyone before trading resumes.

Settlement of Australian cash equities has historically operated on a T+2 basis, meaning settlement occurs two business days after the trade. Settlement arrangements and the timetable are subject to change, and they are set by the settlement operator rather than by individual brokers, so a reader with a specific question about timing should check the operator's current documentation. International readers used to their own market's timetable should not assume the cut-off times or the currencies involved are the same.

Dividends, franking and what the yield leaves out

Australian companies commonly pay dividends twice a year and frequently attach franking credits to them. Franking reflects company tax already paid on the profits distributed, and it can reduce the tax an eligible Australian resident shareholder pays on that dividend.

The important point for understanding market data is that a quoted dividend yield does not incorporate franking. Two companies can show identical headline yields and quite different after-tax outcomes for a particular shareholder, depending on franking and on that shareholder's own tax position. Franking is also not a guaranteed feature of a dividend: it depends on the company's tax position, and companies can and do pay unfranked dividends.

Two further mechanical notes. Dividends are typically declared with a record date and an ex-dividend date, and the share price on the ex-dividend date reflects the fact that a buyer from that date will not receive the dividend. And because yield is calculated against price, a falling share price raises the quoted yield — a rise that says nothing good about the company. Coverage of the dividend, assessed against operating cash flow, is the figure worth checking. How franking affects you personally is a tax question for a registered tax agent.

What the indices actually measure

Index names are widely quoted and frequently misunderstood. The differences between them are not cosmetic.

Index construction rules also specify how constituents are selected and how often the index is rebalanced. A company entering or leaving an index can move its price independently of anything happening in its business, because funds that track the index must buy or sell. This is a mechanical effect of index membership, not a judgment about the company.

A summary of the differences

• Concentration. A small number of large companies, weighted heavily to financials and materials, dominate index outcomes.
• Reporting frequency. Twice-yearly financial reporting, offset by a continuous disclosure obligation that produces news at any time.
• Single dominant venue. One principal listing and trading venue with its own listing rules, rather than competition between multiple primary exchanges.
• Franking. Company tax is commonly attached to dividends as credits, so headline yields do not capture after-tax outcomes.
• Small-cap tail. A long list of very small companies, including many pre-revenue explorers, with wide variation in disclosure quality and analyst coverage.
• Currency. Domestic reporting is in Australian dollars. Comparing an Australian company directly against an overseas peer requires a currency adjustment before any ratio comparison is meaningful.

What this guide does not do

It does not tell you whether the Australian market is attractively priced, whether to hold Australian shares, or how to allocate anything. It explains structure, because structure determines what the data you are reading actually represents. Market rules, settlement arrangements and reporting requirements change, and where a detail matters to a decision you are making, check the current rulebook or the operator's own documentation rather than relying on any summary, including this one.