Investors have grown increasingly fond of index funds, which monitor an underlying market index. A fund may track the S&P 500 or Dow Jones Industrial Average, allowing investors to own each of the indexes' assets.
![]() |
The Uncoverable Variations Between Index Funds |
No fund's performance is guaranteed to be the same as other funds of a similar type, and no fund will definitely mirror the index it monitors even if index funds should mimic their respective indexes. Although the variations between index funds might be modest, they can have a significant influence on an investor's long-term performance.
How to Recognize the Hidden Differences Between Index Funds
Exchange-traded funds (ETFs) that mirror the constituents of an existing financial market index are known as index funds. An index fund is a specific form of ETF that includes a basket of equities or other assets. Index funds, for example, mirror the Standard & Poor's 500 Index. Although investors cannot directly purchase an index, they may invest in index funds that are designed to replicate the index. In other words, an index fund following the S&P 500 would include all 500 equities from the S&P 500. Index funds typically give investors broad market exposure or exposure to an entire industry.
Index funds are therefore passive investments since a portfolio manager does not actively choose stocks by buying and selling assets for the fund. Instead, a fund manager chooses a mix of assets to create a portfolio that is meant to replicate an index. Operating expenses are often lower than those of actively managed funds since the fund's underlying assets are retained rather than actively traded.
At first glance, it may seem fair that the index fund should closely match the index, and that other funds tracking the same index should perform similarly. However, a closer examination reveals major differences across fund kinds.
Ratios of Expenses
The operational expenditures of index funds are perhaps the most noticeable hidden variation between them. The percentage of costs relative to the total amount of assets under-managed on a yearly average is stated as a ratio for these.
Index fund investors could expect cheaper operating expenses because the fund manager does not have to choose or manage any holdings. Operating expenditures, on the other hand, might differ amongst funds. Expenses are critical to consider while investing since they can reduce an investor's profit.
Comparing 10 S&P 500 funds' expenditure ratios as of April 2003, take into account the following comparison:
![]() |
The Uncoverable Variations Between Index Funds |
The many bars in this graphic reflect various funds. Keep in mind that the S&P 500 had an annual return of around 5% as of the end of April 2003, with expenditure ratios ranging from 0.15% to over 1.60%. A fund fee ratio of 1.60% will roughly cut an investor's return by 30% if we assume that the fund closely tracks the index.
Fees
Fee structures for index funds with essentially identical portfolio mixes and investment techniques might differ. Some index funds have front-end loads, which are fees or sales costs paid upfront when an investment is purchased for the first time. Other funds have back-end loads, which are fees and commissions levied when an investment is sold. Other expenses include 12b-1 fees, which are the fund's yearly distribution or marketing fees. The 12b-1 fee, however, may be assessed separately or included in the expense ratio of the fund.
Before purchasing an index fund, the fees and expense ratio should be evaluated. Some funds may appear to be a better investment since they have a low expense ratio, but they may also levy a back-end load or a 12b-1 fee. When fees and expenses are added together, they can have a significant influence on an investor's overall return.
Fees are often cheaper in larger, more established funds. For example, as of April 29, 2021, the Vanguard 500 Index Admiral Shares fund (VFIAX), which follows the equities of 500 of the major U.S. corporations, carries a 0.04% expense ratio.
Lower costs might be due to management's experience watching indexes, as well as a greater asset base, which could improve the capacity to leverage economies of scale when acquiring assets. When big businesses can purchase in bulk and reduce the cost per unit, they may save money and benefit from economies of scale.
Error Tracking
Comparing tracking mistakes and measuring each fund's departure from the index it imitates are two more techniques for conducting effective index fund evaluations.
Monitoring error quantifies the amount of divergence between the fund's value and the index it is tracking. The tracking error is often reported as a standard deviation, which indicates how much difference or dispersion occurs between the fund's price and the underlying index's average or mean price. Significant deviations show significant discrepancies between the benchmark and an index fund's performance.
This big disparity may indicate inadequate fund construction, exorbitant fees, or operational expenditures. Due to high expenditures, the return on an index fund may be much lower than the return on the index, resulting in a severe tracking error. As a result, any variation might result in the fund making lesser profits and suffering higher losses.
The graph below compares the returns of the S&P 500 (red), Vanguard 500 Index Admiral Shares (green), Dreyfus S&P 500 (blue), and Advantus Index 500 B. (purple). As expenditures rise, the index fund's deviation from the benchmark rises.
The Assets of a Fund
A fund's name may not always imply that it closely reflects the underlying index or sector. When looking for an index fund, keep in mind that not all index funds labeled "S&P 500" or "Wilshire 5000" only track those indices. Divergent management behavior can occur in some funds. In other words, a portfolio manager may add equities comparable to those in the index to the fund.
Consider the Devcap Shared Return fund, a socially responsible S&P 500 index fund. It had an expenditure ratio of 1.75% as of June 4, 2003, and charged a 12b-1 fee of 0.25%. Another fund, the ASAF Bernstein Managed Index 500 B, was labeled as an S&P 500 index fund but intended to exceed it.
![]() |
The Uncoverable Variations Between Index Funds |
The inclusion of securities in sector index funds, which monitor specific economic sectors, is frequently subject to the investment manager's subjective judgment. The SPDR S&P Homebuilders exchange-traded fund (XHB), for example, is well-known for tracking equities in the homebuilding business. An investor purchasing the fund may believe it comprises just homebuilders. Some assets, however, are equities of firms in the industry. Whirlpool Corporation (WHR), the appliance maker, Home Depot (HD), the home supply shop, and Aaron's Inc., a rent-to-own furniture retailer, are all featured.
In addition, if an index fund's portfolio manager provides extra management services, the fund is no longer passive. In other words, a fund's purpose may seek to beat an index, such as the S&P 500, which may lead to holdings that include firms and securities not included in the index being monitored. As a result, funds with these enhanced selling features generally have fees that are significantly higher than the norm.
Before investing in an index fund, investors should examine its holdings to discover whether it is a real index fund or a fund with an index-like moniker.
Diversification Is Lacking
Not all of the index funds listed are as diverse as those that track an index such as the S&P 500. Many index funds have characteristics with targeted, value, or sector funds. However, keep in mind that specialized funds often own fewer than 30 stocks or assets in the same sector. The lack of diversity in sector funds might expose investors to greater risk than a fund following the S&P 500, which is made up of 500 businesses from diverse industries.
Particular Considerations
Before purchasing index funds, be certain that there are few to no tracking mistakes and that the fees and costs ratios are minimal. Also, understand the investment manager's purpose for the index fund and what assets or investments are included to achieve that goal. The fund's investments may differ from the underlying index if the aim is thought to be aggressive.
Fees become even more relevant in light of growing risk factors - fees diminish the amount of return gained for the risks incurred. Consider the following Dow 30 index fund comparison:
![]() |
The Uncoverable Variations Between Index Funds |
The risk tolerance and time horizon of an investor might influence investment selection. A retiree is likely to select index funds that are conservative or low-risk, as the purpose is to preserve the portfolio while still providing income.
A Millennial, on the other hand, may pick a fund with a more aggressive investing strategy aimed to provide growth because the Millennial has more time to recover from any market downturns. When it comes to selecting an index fund, risk tolerance and time horizon are both critical factors to consider.