What is an ETF?
An ETF — exchange-traded fund — is a type of fund that you buy and sell on a stock exchange, just like an individual share. Most ETFs are designed to track an index rather than actively picking investments. They have become one of the most widely used tools for long-term passive investing.
How an ETF works in practice
When you buy a share of a global ETF, you are buying a tiny slice of every company the ETF holds. A single share of Vanguard's FTSE All-World ETF (ticker: VWRP), for example, gives you exposure to over 3,500 companies across more than 50 countries — in one transaction.
The ETF itself holds those underlying shares and updates automatically as indexes change. You do not need to manage any of this. Your job is simply to hold the ETF and let compounding do its work over time.
How ETFs differ from traditional funds
Traditional funds — often called unit trusts or OEICs in the UK — are priced once per day and dealt directly through the fund provider. ETFs trade on an exchange in real time throughout the trading day, just like shares.
In practice, for a long-term investor who buys monthly and holds for years, this difference matters very little. You are not trying to time the market, so intraday pricing is irrelevant. What matters is cost, coverage, and fit with your plan.
Why ETFs are popular for long-term investing
- Low cost. Most index-tracking ETFs charge between 0.05% and 0.25% annually. That compares very favourably with actively managed funds charging 0.75% to 1.5%.
- Instant diversification. A single global ETF can hold thousands of companies.
- Simplicity. One holding, one annual cost, no stock picking required.
- Tax efficiency inside an ISA. Held within a Stocks and Shares ISA, all ETF growth and dividends are tax-free.
Accumulation vs income ETFs
ETFs come in two flavours. Accumulation (often marked "Acc") automatically reinvests any dividends back into the fund — your holding grows in value. Income (often marked "Inc" or "Dist") pays dividends out as cash to your account.
For long-term wealth building, accumulation is usually preferable because it keeps compounding working without requiring you to manually reinvest. For those who want income — for example, in retirement — income ETFs are more useful.
What still matters when choosing an ETF
ETF does not automatically mean better. Before choosing one, check:
- What does it actually track? A US-only ETF is very different from a global one.
- What is the OCF? Lower is generally better for passive investing.
- How large is it? Larger, more established ETFs are generally more stable and liquid.
- Does it fit your plan? An ETF that overlaps heavily with others you hold adds complexity without benefit.
Read One fund vs three funds to understand when a single ETF may be all you need, or use the planning calculators to check for overlap in what you already hold.