How the Stock Market Works

The stock market for beginners can look like forex with company names attached: a price, a chart, a buy button. Underneath, the two work very differently. A currency trade is a bet on one money against another. A share is a small, legal piece of a business, and its long-run value depends on what that business earns.

What exactly do I get when I buy a share?

Short answer: part-ownership of a company, which usually carries a right to a share of distributed profits and a vote at shareholder meetings.

When a company lists on an exchange it divides its ownership into shares. Buy one and you own a sliver of everything the company has and a claim on what it will earn, after its debts. If the board decides to pay out part of the profit, you receive a dividend in proportion to your holding. If the company is taken over, you are paid for your shares. If it fails, shareholders are last in line behind lenders and suppliers, and often receive nothing.

Ordinary shares normally carry voting rights on matters such as electing directors. Some companies issue several share classes with different voting power, so it is worth knowing which class you are buying.

How does an order reach the exchange?

Private investors do not deal with an exchange directly. You place an order with a licensed broker, which sends it to an exchange or another regulated venue where it meets an opposite order. Two order types cover most needs:

• Market order: deal immediately at whatever the best current price is. Quick to fill, although a small, rarely traded company can fill you some way from the quote on screen.
• Limit order: name a ceiling for a purchase or a floor for a sale. The price is protected, but the order may sit unfilled.

After the trade, the broker usually holds the shares in a nominee account: the register shows the nominee as the legal owner, with you as the beneficial owner. Regulated brokers must keep client assets separate from their own, so a broker's failure should not mean the loss of your shares, though sorting it out can take time.

When are stock exchanges open?

Outside these sessions there is little or no trading, so company results released after the close show up as a gap at the next open. That is a big contrast with forex, which runs continuously through the week.

How long until the trade is final?

US share trades have settled on T+1 since May 2024: the shares and the cash change hands one business day after the trade date. Other markets have their own cycles. Settlement matters mostly for when sale proceeds can be withdrawn and for corporate events such as dividends, where you need to own the shares before the ex-dividend date to receive the payment.

What do stock market indices measure?

An index tracks a defined basket of shares so that one number can summarise how a market moved. The construction rules matter:

• S&P 500: around 500 large US companies, weighted by float-adjusted market capitalisation, so the biggest companies move it most.
• Dow Jones Industrial Average: 30 US companies, weighted by share price, so a high-priced share carries more weight regardless of the company's size.
• Nasdaq Composite covers all shares listed on Nasdaq, while the Nasdaq-100 takes the largest non-financial ones.
• FTSE 100, DAX (40 German companies, calculated as a total-return index that assumes dividends are reinvested), Nikkei 225 (price-weighted), ASX 200, Nifty 50 and Sensex (30 companies on the BSE).

You cannot buy an index itself. Index funds and exchange-traded funds hold the underlying shares to track it, and CFD providers offer contracts on index prices, which bring leverage and overnight charges with them.

How do investors judge whether a share is expensive?

Price alone says nothing: a $400 share can be cheaper, relative to its earnings, than a $4 one. Two simple ratios help put a price in context. Here is an illustrative company whose shares cost $80 and which earned $4 per share last year while paying $2.40 in dividends:

A P/E of 20 means buyers are paying 20 years of last year's profit. Whether that is high depends on how fast earnings are expected to grow and on what other investments are paying. Ratios are a starting point for questions, not answers.

Is buying shares investing or trading?

Either, depending on how long you hold and why. Investing usually means owning shares or funds for years and relying on company earnings and dividends to drive returns; costs are paid once and time smooths out much of the day-to-day noise. Trading means holding for days or hours to profit from price swings, which makes spreads, commission and timing far more important. Many readers who come from currency trading underestimate how different the two approaches feel: a long-term shareholder can ignore a bad week, while a leveraged share trader cannot.

What happens at corporate events?

Companies change their share structure from time to time, and each event affects your holding differently:

• Share split: each share becomes several cheaper ones; the total value of your holding does not change.
• Rights issue: existing shareholders are offered new shares, often at a discount. Ignoring the offer can dilute your stake.
• Buyback: the company purchases its own shares, reducing the number outstanding.
• Takeover: another company offers to buy all the shares, for cash, shares of its own or both.

Your broker should notify you of events that need a decision, but deadlines are often short, so it pays to read those messages.

What costs come with buying shares?

Buying 25 shares at $80 costs $2,000 plus charges, which can include a dealing commission, a platform or custody fee, a currency conversion fee if you buy shares priced in a different currency, and in some countries a transaction tax on purchases. The spread between bid and ask is usually narrow on large companies and wider on small ones. Our guide to trading costs explains how to add these up and compare them fairly.

Some countries also offer tax-sheltered wrappers. In the UK, for example, the ISA allowance is £20,000 for the 2026/27 tax year.

Which risks matter most in the stock market for beginners?

• Company risk: one business can fail even when the market rises. Holding many companies, directly or through a fund, spreads this.
• Market risk: whole markets can fall by a third or more and take years to recover.
• Currency risk: a UK investor holding US shares gains or loses as GBP/USD moves, on top of the share price.
• Leverage risk: share CFDs are capped at 5:1 for retail clients in the UK and EU, but even 5:1 turns a 20% fall into the loss of the whole margin.

If you are comparing shares with currencies or crypto, the market structure explainer lines them up side by side, and our broker checklist covers what to confirm before you hand money to any intermediary.

Sources

• US Securities and Exchange Commission, T+1 settlement cycle
• S&P Dow Jones Indices, index methodology documents
• HM Revenue & Customs, ISA allowances