Largest index funds by AUM and how to invest in them

The information, data and examples (including fund names, expense ratios and Assets Under Management) are based on publicly available sources as of November 2025 and may change without notice. References to specific funds or issuers are for illustrative purposes and don’t constitute a recommendation or endorsement.

What are index funds?

Index funds are investment funds designed to follow the performance of a specific market index, such as one that tracks large US companies or global markets. Their goal is to match the performance of that index as closely as possible, rather than trying to beat it.

Unlike actively managed funds – where professional managers choose individual stocks – index funds use a passive strategy. This means they automatically replicate the holdings of their chosen index, offering investors broad market exposure in a simple, transparent way.

Well-known examples include:

• S&P 500: Tracks the 500 biggest publicly traded companies in the United States, covering all major industries. It’s considered a benchmark for the overall US stock market.
• Nasdaq 100: Focuses on 100 of the largest non-financial companies listed on the Nasdaq exchange, making it heavily weighted toward tech giants.
• Dow Jones Industrial Average: Tracks 30 large, established US companies across sectors like healthcare, finance and manufacturing. It’s often used as a shorthand for the strength of the overall economy.

You can buy index funds as mutual funds or ETFs (exchange-traded funds). ETFs trade like stocks during the day; mutual funds trade once at market close. Both can track the same index.

Over long periods, broad US index funds have delivered around 10% average annual returns. Though returns vary from year to year, the long-term trend has been strong.

Index funds vs ETFs: What’s the difference?

An index fund refers to an investment approach designed to track the performance of a specific market index. An ETF refers to the structure of the product – a pooled investment vehicle that trades on an exchange throughout the day, similar to a stock.

Many ETFs follow an index, which means they can also be considered index funds. For example, some ETFs aim to mirror the same benchmarks as index mutual funds, but they differ in how investors can access them.

Both structures are designed to provide diversified market exposure. The choice between them depends on an investor’s platform preferences, trading habits and account type. 

Note: We offer ETFs via Crypto.com Stocks, but we don’t offer traditional stock index funds.

Why are index funds popular?

Index funds have become widely used by investors who prefer a simpler, rules-based way to gain exposure to financial markets. Their popularity is largely due to several structural features rather than performance expectations:

• Transparent costs: Index funds clearly disclose their management fees (known as expense ratios), which are typically lower than those of actively managed funds.
• Broad exposure: A single fund can hold a wide range of securities that mirror a chosen market index, providing built-in diversification.
• Predictable objective: The goal of an index fund is to replicate the performance of its benchmark index, not to outperform it.
• Ease of access: They can often be bought and sold through most investment platforms, including via ETF formats.
• Market adoption: Industry data from research providers such as Bloomberg show that index-tracking products now represent a substantial portion of US equity fund assets (as of 2025).

Top 10 index funds by AUM and expense ratio* (2025)

Sources: Morningstar, ETFdb, Bloomberg, Vanguard, Invesco (as of November 2025).
(AUM values rounded; may fluctuate daily.)

Why AUM and fees matter

• AUM (Assets Under Management) shows how much investor money is in the fund – a key indicator of trust, liquidity and stability.
• Expense ratio tells you how much you pay each year to own it. A 0.03% fee means you pay $3 per $10,000 invested annually.

Benefits and risks of index funds

Key features often viewed as benefits

• Cost efficiency: Index funds generally have clearly disclosed management fees (expense ratios), which are often lower than those of actively managed funds.
• Diversification: A single fund can hold many securities across various sectors, providing exposure that mirrors a broader market index.
• Transparency: Fund holdings are typically published regularly, allowing investors to see which securities make up the index.
• Defined objective: The fund’s goal is to replicate an index’s performance as closely as possible, which removes the need for active stock selection.
• Ease of access: Many index-tracking products are widely available through mutual-fund and ETF formats.

Common risks and considerations

• Market risk: Because index funds track the market, their value will rise and fall in line with overall market movements.
• No active management: These funds aim to match an index, so they won’t attempt to outperform it.
• Concentration risk: Some indexes may have significant exposure to specific sectors or large individual companies, which can affect volatility.
• Tracking difference: Minor variations between a fund’s returns and its benchmark can occur due to fees, cash holdings or rebalancing methods.

How to invest in index funds (step by step)

1. Research your options

Begin by understanding the different types of index-tracking funds available. Each fund follows a specific market segment or index – for example, broad US equities, global markets or particular sectors.

When comparing options, review key factors such as:

• Expense ratios: The annual management fee charged by the fund.
• Assets under management: The total size of the fund, which can indicate scale and liquidity.
• Index coverage: The range of companies or markets the fund aims to replicate.

Always refer to the latest fund fact sheet or prospectus to understand its investment objective, composition and associated costs.

2. Choose a platform

Look for a regulated investment platform that offers access to index funds or exchange-traded funds.

On the Crypto.com App, you can explore and invest in a range of ETFs with 0% trading commissions. These ETFs provide diversified market exposure similar to index funds but are traded on an exchange throughout the day.

3. Decide how much to invest

When considering how much to allocate, some investors choose to make a single purchase, while others prefer to invest smaller amounts at regular intervals – a method known as Dollar-Cost Averaging (DCA).

DCA involves investing a fixed amount on a set schedule regardless of market movements, which results in purchases at varying price levels over time. This is a commonly used approach to help manage the timing of investments, but it doesn’t guarantee profit or protect against loss.

4. Make your first purchase

You can explore and trade ETFs through the Stocks section of the Crypto.com App. You can search for different ETFs, review their details such as objectives and costs, and place an order directly within the App.

5. Monitor and rebalance periodically

It can be useful to review your portfolio from time to time to ensure it continues to reflect your intended investment approach. If certain holdings have increased or decreased in value relative to others, some investors choose to adjust their allocations to maintain their preferred balance.

Investors who seek broader diversification may also look at funds that provide exposure to different regions or markets. Any decision to adjust holdings should take into account personal objectives, risk tolerance and the information provided in each fund’s documentation.

Ready to invest?

1. Sign up to Crypto.com and create a Crypto.com Stocks account.
2. Verify your identity and add funds to your account.
3. Explore stocks, ETFs or fractional shares. 
4. Start building an investment portfolio today.

FAQs about index funds

Are ETFs and index funds the same thing?

Not exactly. An index fund describes an investment approach that aims to follow the performance of a specific market index. An ETF (exchange-traded fund) refers to the structure – a pooled investment that trades on an exchange throughout the day. Many ETFs track indexes, so an ETF can also function as an index-tracking product, depending on its objective.

Does Crypto.com Stocks offer index funds?

Crypto.com Stocks currently offers access to ETFs, not traditional stock index mutual funds. Many available ETFs are designed to follow major market indexes, providing diversified exposure. Product availability and eligibility may vary depending on the user’s region and applicable regulations.

What does 0% commission mean for ETFs on Crypto.com Stocks?

0% commission means that we don’t charge a trading commission when buying or selling ETFs. Other costs, such as the ETF’s management fee (expense ratio) or bid-ask spread, may still apply. Users should review all applicable costs before trading.

Does Crypto.com Stocks offer fractional investing?

Yes, Crypto.com Stocks offers fractional share investing for certain equities, allowing users to purchase a portion of a company’s stock rather than a full share. 

Are ETFs risk free?

No, ETFs involve investment risk, including the possible loss of capital. Their value may fluctuate with changes in market conditions and past performance doesn't guarantee future results. Before investing, review each ETF’s objectives, risks and costs to ensure you understand how it works.

* Data such as AUM and expense ratios are approximate and can change; always check the latest fund fact sheet.

This is informational content sponsored by Crypto.com and should not be considered as investment advice.

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All investments involve risk, and not all risks are suitable for every investor. The value of securities may fluctuate and as a result, clients may lose more than their original investment. The past performance of a security, or financial product does not guarantee future results or returns. Keep in mind that while diversification may help spread risk, it does not assure a profit or protect against loss in a down market. There is always the potential of losing money when you invest in securities or other financial products. Investors should consider their investment objectives and risks carefully before investing.