How the Stock Market Works

The stock market for beginners is often explained through charts and ticker symbols, but the more useful starting point is ownership. A share is a small, legally defined piece of a company. Once you understand what that piece entitles you to, most of the rest, from dividends to indices to why prices react to earnings, follows naturally.

What does owning a share actually give you?

A proportional claim on the company's profits and assets, and usually a vote on major decisions.

If a company has 100 million shares and you own 1,000, you own a millionth of it. You do not get to walk into the office, but you are entitled to your share of any dividend the board declares and, if the company is sold or wound up, a share of what is left after creditors are paid. Ordinary shareholders usually also vote on directors and major corporate changes.

Because shareholders are paid last, shares carry more risk than lending to the same company. That extra risk is the reason investors expect higher returns from shares over long periods, though there is no guarantee over any particular period.

How do shares get onto an exchange?

Through a listing, usually an initial public offering, after which shares trade between investors rather than with the company.

When a company lists, it sells shares to investors and meets the exchange's rules on disclosure and governance. From then on, almost all trading happens between investors; when you buy a share, the money goes to another investor, not to the company. The company's link to the price is indirect: a higher share price makes it cheaper to raise money later and affects how management is paid.

Where and when are shares traded?

On national exchanges during local business hours, with prices mostly frozen outside them.

Some brokers offer extended-hours trading before and after the main US session, but volumes are lower and spreads wider. When significant news breaks overnight, the price at the next open can be far from the previous close, a gap that stop orders cannot prevent.

What happens between placing an order and owning the share?

Your broker sends the order to a venue, it is matched, and ownership transfers at settlement.

Two order types cover most needs. A market order buys immediately at the best available price, which is fast but can fill at a worse price than you saw in a thin or fast market. A limit order sets the highest price you will pay (or lowest you will accept when selling), so it controls price but may not fill at all.

After the match, the trade settles. In the United States that happens one business day after the trade (T+1). Your broker then holds the shares in a nominee account on your behalf. In many countries, client assets must be kept separate from the broker's own money, and compensation schemes may cover some shortfalls if a broker fails, up to set limits.

A note for US readers who trade frequently: the long-standing pattern day trader rule, with its $25,000 minimum, has been replaced. The SEC approved FINRA's new framework on 14 April 2026, and it took effect on 4 June 2026, using intraday margin requirements instead. Check how your own broker has implemented it.

How do investors actually make or lose money?

Through price changes and dividends together, known as total return.

An illustrative example: you buy 20 shares at $50, a $1,000 outlay. Over a year the company pays four quarterly dividends of $0.40 per share, which is $32 in total. The price rises to $54, a paper gain of $80. Your total return is $112, or 11.2%, before tax and any trading costs. Had the price fallen to $46 instead, the $80 loss would have outweighed the dividends, leaving you $48 down.

Prices move mainly on changing expectations about future profits. A company can report record earnings and still see its shares fall if investors expected even more. That is why share prices often react more to guidance and surprises than to the headline numbers.

How do investors put a value on a share?

Usually by comparing the price with the profits, cash flows or assets behind it.

The most quoted yardstick is the price-to-earnings ratio. As an illustration, a company earning $2 per share with a share price of $40 has a P/E of 20: investors pay $20 for each $1 of annual profit. Turned upside down, that is an earnings yield of 5%. A high ratio signals that investors expect profits to grow; a low one can signal doubt, or a bargain, and the ratio alone cannot tell you which. Analysts also look at cash flow, debt, dividends and how a business compares with its competitors. None of these measures predicts next month's price, which is driven as much by sentiment as by arithmetic.

How do companies return money to shareholders?

Through dividends, share buybacks, or by reinvesting profits to grow the business.

A dividend is cash paid per share, usually quarterly in the US and half-yearly in the UK. To receive it you must own the share before the ex-dividend date; buying on or after that date means the seller keeps the payment, and the price typically drops by roughly the dividend amount when the share goes ex-dividend. A buyback uses the company's cash to purchase its own shares, which reduces the number in issue and raises each remaining share's slice of future profits. Many growth companies pay neither, preferring to reinvest.

What is an index, and why does everyone quote them?

An index tracks a defined basket of shares to summarise how a market or sector is doing.

The S&P 500 covers about 500 large US companies weighted by float-adjusted market value. The Dow Jones Industrial Average holds just 30 companies and is price-weighted, so a high-priced share moves it more regardless of company size. The Nasdaq Composite includes all companies listed on Nasdaq, while the Nasdaq-100 takes the largest non-financial names. Elsewhere, the FTSE 100, the DAX (40 German companies, calculated as a total-return index), the Nikkei 225 (also price-weighted) and the Nifty 50 are the common reference points. Index funds and ETFs let investors buy an entire index in one transaction, which is the simplest way to avoid the concentration risk of owning a handful of companies.

How is buying shares different from trading share CFDs?

Buying a share gives ownership; a CFD only tracks the price, usually with leverage and overnight charges.

With a share CFD you never own the company, so you have no vote and receive only a cash adjustment for dividends. Retail leverage on individual share CFDs is capped at 5:1 in the UK and EU, which still means a 20% fall can wipe out the margin. CFDs are designed for short-term trading; the financing charge makes them expensive to hold for long.

Stock market for beginners: what are the main risks?

• Company risk: a single business can fail or shrink permanently. Diversification reduces this; nothing removes it for an individual share.
• Market risk: broad markets can fall a long way and stay down for years.
• Currency risk: buying foreign shares adds exposure to the exchange rate, which can help or hurt.
• Cost drag: commissions, spreads, currency conversion and fund fees compound over time. See hidden trading costs.
• Behaviour: selling after falls and buying after rallies is the most common way investors turn a reasonable market return into a poor personal one.

UK readers can shelter up to £20,000 a year from tax in ISAs for 2026/27; tax treatment elsewhere varies, and none of this is tax advice. Before choosing any broker, work through our pre-account checklist.

Sources

• US Securities and Exchange Commission, T+1 settlement cycle
• FINRA, amendments to pattern day trading rules approved by the SEC in April 2026
• Exchange websites for regular trading hours
• HM Revenue and Customs, ISA allowances