Index Funds: A Simple and Affordable Path to Investment Success
In recent years, index funds have emerged as a remarkably accessible and cost-effective avenue for investors, proving to be a lucrative strategy for many. Unlike traditional actively managed funds where a professional manager attempts to outperform the market by strategically selecting assets, index trackers operate on a simpler principle: they mirror a specific market index.
The spectrum of index fund options is broad, ranging from those that track the performance of the entire global stock market to more focused funds that follow the trajectory of a particular country’s stock market, such as the S&P/ASX 200 in Australia, or a diverse basket of other investment types. The key characteristic of any index fund is that the index it tracks must be clearly defined. Investment decisions, including the buying and selling of holdings, are executed by computerised systems following a predetermined set of rules. This approach is termed “passive investing,” a distinct contrast to “active investing” where fund managers make discretionary choices. Passive funds aim to hold every component of their designated index, thereby replicating its performance precisely. While this means they won’t necessarily ‘beat’ the market, they also avoid the risk of underperforming due to unsuccessful investment decisions. Furthermore, the cost savings are substantial. An active fund manager might levy annual charges of 0.7 per cent or more on global fund holdings, whereas an index fund could charge a mere fraction, often less than 0.2 per cent.
The Ascendancy of Index Investing
The popularity of index funds experienced a significant surge in the 1990s when they became widely available to individual investors, though they had been a staple for large institutional investors for decades prior. This trend has only accelerated over the last ten years. Data from the Investment Company Factbook 2025 indicates that a substantial 51 per cent of assets within long-term US mutual funds are now held in index tracking funds.
The remarkable performance of the US stock market has been a primary driver behind the growing appeal of index funds. Given that the US market constitutes approximately 72 per cent of the global stock market, as measured by the MSCI World Index, investments tracking US indices have yielded impressive returns. For instance, an Australian investor holding a fund that tracks the S&P 500, the leading US stock market index, would have seen a total return of around 83 per cent over the past five years. Similarly, an investment in a global index fund like Fidelity’s Index World, which tracks the MSCI World Index, would have delivered approximately 92 per cent in returns over the same period.
Tracker Funds Versus ETFs: Understanding the Differences
Index funds generally come in two primary structures: traditional investment funds and Exchange-Traded Funds (ETFs).
Index Investment Funds: These funds are bought and sold by investors in units. The value of these units fluctuates directly with the value of the underlying assets held by the fund. Pricing for these funds typically occurs once per day.
Exchange-Traded Funds (ETFs): ETFs have seen a dramatic surge in popularity recently. They are traded on the stock market, meaning they can be bought and sold in the same manner as individual company shares. ETFs are priced continuously throughout the trading day, featuring an ‘ask’ price for buyers and a ‘bid’ price for sellers. The difference between these two prices is known as the bid-ask spread, and a narrow spread generally signifies high demand for the ETF.
Despite these structural differences, both index tracking funds and ETFs function on the same core principle of passive investing. The choice between the two often boils down to personal preference and the specific offerings and fee structures of an investor’s chosen DIY investment platform.
For those seeking a highly simplified investment portfolio, a single broad global index fund can be an effective solution. This approach allows investors to gain exposure to approximately 4,000 companies worldwide at a low cost. However, it’s important to acknowledge that such a strategy can lead to significant dependence on the US market and its dominant technology companies. For example, in some global ETFs, individual companies like Nvidia might represent a substantial percentage of the fund’s holdings (e.g., 4.6 per cent), while an entire national stock market, like the UK’s, might constitute a much smaller portion (around 3 per cent).
To mitigate over-reliance on the US market, investors can strategically diversify their portfolios. This might involve holding the majority of their investments in a global index fund and then augmenting this with increased exposure to other regions through single-country index funds or funds focused on specific asset classes like gold, bonds, or particular investment themes. It’s crucial to understand that deviating from a single, broad market-tracking index means moving away from pure passive market-following investing.
Navigating the Nuances of Index Funds
While index funds are celebrated for their accessibility and cost-effectiveness, it’s important to recognise that not all are created equal. Some funds may impose higher charges than their competitors, despite offering the same investment strategy. Others might exhibit a greater tendency for their returns to deviate from the index they are meant to track.
A paramount consideration when selecting an index fund is its cost. There is little benefit in opting for index investing only to choose a fund burdened with high fees. Investors must also scrutinise the composition of the index itself to understand precisely what they are investing in. This is particularly vital for broad global tracker funds, as some may omit certain markets that an investor might reasonably expect to be included. For instance, the MSCI World index does not encompass emerging markets, whereas the MSCI All Countries World Index does.
Another critical factor to monitor is “tracking error.” This refers to the extent to which a tracker fund fails to precisely replicate the performance of its benchmark index. While typically small, tracking error can become more pronounced over extended periods. Therefore, it’s advisable to consistently compare a fund’s performance against its stated index and to seek out data on tracking error provided by your investment platform.
Sample Index Fund and ETF Options for Consideration
Here are some examples of index funds and ETFs available, categorised by the market they track, along with their approximate ongoing charges:
UK Stock Market
- Index Fund: HSBC FTSE All-Share Index, ongoing charges 0.07%
- ETF: iShares Core FTSE 100 Fund, ongoing charges 0.07%
US Stock Market
- Index Fund: Legal & General US Index, ongoing charges 0.1%
- ETF: Vanguard S&P 500, ongoing charges 0.07%
Global Stock Market
- Index Fund: Fidelity Index World, ongoing charges 0.12% (Tracks MSCI World Index, excluding emerging markets)
- ETF: Vanguard FTSE All World (VWRL), ongoing charges 0.19% (Tracks FTSE All World Index, including emerging markets)
- ETF: iShares MSCI ACWI (SSAC), ongoing charges 0.2% (Tracks MSCI All Countries World Index, including emerging markets)
