The stock market is not a club for insiders, and exchange-traded funds (ETFs) are perhaps the clearest proof. A first-time investor can easily own a slice of the world's largest companies without picking a single share. The trick is knowing where to begin.

1. Understand what you are buying

An ETF is a basket of shares or bonds that tracks an index, such as the S&P 500 or the FTSE 100. Rather than bet on a single company, you buy the whole market in one trade. When the index rises, your ETF rises; when it falls, it falls too. Its mechanism remains simple, transparent and inexpensive. It is precisely that simplicity and low cost which have won over millions of investors.

2. Be clear about your goal and your horizon

Before you open any account, ask yourself one question: when will you need this money? An equity ETF suits a distant goal such as retirement, a child's education, or wealth built over ten years or more. It is a poor fit if you plan to buy a house in two years. Markets fluctuate; time is your best ally in absorbing those swings. A simple rule: invest only money you can do without for several years.

3. Select your ETF

Faced with thousands of ETFs, three criteria are enough to start. First, the index it tracks: a broad global index is the simplest choice for a first investment, spreading your money across hundreds of companies and dozens of countries. Second, the annual fee: aim for less than 0.4 per cent a year - over twenty years, the difference runs into thousands. Third, the size of the fund: a large pool of assets is usually a sign of resilience and liquidity. There is no need to collect ETFs; one or two, well chosen, are plenty.

4. Buy and hold

That leaves the question that paralyses so many beginners: is this the right moment? Instead of buying it all at once, you might invest a fixed sum every month or quarter, whatever the price. You will sometimes buy high and sometimes low, smoothing your average price without thinking about it. Above all, resist the urge to sell at the first storm.