Index Funds Explained: Low-Cost Investing

What Is an Index Fund?

An index fund is a type of investment fund that aims to replicate the performance of a specific market index. Instead of paying a fund manager to pick stocks, the fund simply holds all the companies in the index in proportion to their size.

For example, a FTSE 100 index fund holds shares in all 100 companies in the FTSE 100, weighted by market capitalisation. When the index rises, the fund rises. When it falls, the fund falls. No human judgement is involved.

Why Index Funds Win

The case for index investing rests on one powerful fact: most professional fund managers fail to beat the market over time.

The S&P SPIVA scorecard — the most comprehensive study of active vs passive performance — consistently shows that over 15-year periods, approximately 85–90% of actively managed funds underperform their benchmark index after fees.

This is not because fund managers are incompetent. In aggregate, they are the market — and after fees, they must underperform the market. Index funds simply capture the market return at minimal cost.

The Cost Advantage

Fees are the key differentiator:

• Index funds: 0.06%–0.25% annual charge (OCF)
• Active funds: 0.75%–1.50% annual charge

On a A$100,000 portfolio over 30 years at 7% growth, a 1% fee difference costs over A$75,000 in lost returns. Low fees are the single most reliable predictor of future fund performance.

Popular Index Funds for Australia Investors

Global Equity

• Vanguard FTSE Global All Cap Index (0.23%) — Over 7,000 companies across developed and emerging markets
• Fidelity Index World (0.12%) — Tracks the MSCI World Index of developed market stocks
• HSBC FTSE All-World Index (0.13%) — Broad global exposure at very low cost

Australia Equity

• Vanguard FTSE Australia All Share Index (0.06%) — Complete Australia market exposure
• Legal & General Australia Index (0.04%) — One of the cheapest Australia trackers

Bond Funds

• Vanguard Australia Government Bond Index (0.12%) — Australia gilts for portfolio stability
• Vanguard Global Bond Index (0.15%) — Diversified global fixed income

How to Get Started

1. Choose a platform: Vanguard (low-cost, limited range), interactive investor (flat fee, wide range), or AJ Bell (flexible, good tools)
2. Open an ISA or SIPP: Shelter your investments from tax
3. Select your fund: A single global equity index fund is sufficient for most beginners
4. Set up a monthly contribution: Automate your investing to remove emotion and build discipline
5. Leave it alone: Resist the urge to check daily. Review annually and rebalance if needed.

The Endorsement of Warren Buffett

The world's most successful investor has repeatedly recommended index funds for ordinary investors. In his 2013 letter to Berkshire Hathaway shareholders, Buffett wrote that his instructions for his wife's inheritance were to put 90% in a very low-cost S&P 500 index fund. He has won public bets against hedge fund managers using nothing more than a simple index fund.