Investing term
What is Index fund?
A fund that passively holds every stock in a named benchmark (S&P 500, MSCI World, etc.) in proportion.
An index fund holds every stock in a named benchmark — like the S&P 500 — in the same proportions, aiming simply to match the index rather than beat it. There's no manager trying to pick winners; the fund just owns the whole market it tracks and accepts its return.
Because no expensive research team is involved, fees are minimal — often a few hundredths of a percent. Decades of evidence show this humble approach beats most active funds over the long run, precisely because it doesn't try to be clever and doesn't charge much to do it. That combination of broad diversification and rock-bottom cost is why index funds are the backbone of low-cost investing.
An index fund holds every company in its benchmark, in proportion, for a sliver of a fee. It matches the market rather than beating it — and by doing so quietly outperforms most active funds.
For example
An S&P 500 index fund just owns all 500 companies as they are — you get the market's return minus a fee so small it's almost an afterthought.
Learn it by doing
That's Index fund in theory — it clicks when you use it. Practise it hands-on in a free, interactive lesson (Stage 6, Index Funds, ETFs & Mutual Funds).
Try the free lesson →Why it matters to you
Index funds matter because they turn a hard problem — beating the market — into an easy one: just owning it, cheaply. By capturing the market's return minus a tiny fee, they quietly outperform the majority of active funds over long periods, without requiring the investor to analyse a single company. For most people, a broad index fund is the simplest, most reliable core of a portfolio.
⚠ Thinking 'average' means mediocre
An index fund earns the market's return, which sounds merely average — but because most active funds trail the market after fees, 'average' actually beats the majority of professional stock-pickers over time. Dismissing index funds as settling for the middle misreads the evidence: matching the market cheaply is a winning strategy, not a resigned one.