Types of Index Fund
There are four main categories of index funds, organized by their underlying investment strategies: Equity Index Funds, Bond Index Funds, Commodity Index Funds, and Hybrid Index Funds.
Main Categories
- Equity Index Funds — track a specific stock market index, such as the S&P 500, and hold a portfolio of stocks that replicates the index's composition, like Vanguard 500 Index Fund.
- Bond Index Funds — invest in a diversified portfolio of bonds that mirrors a particular bond market index, such as the Bloomberg Barclays US Aggregate Bond Index, like iShares Core US Aggregate Bond ETF.
- Commodity Index Funds — track the performance of a specific commodity index, such as the Goldman Sachs Commodity Index, and hold a portfolio of commodity futures contracts or other derivative instruments, like Invesco DB Commodity Index Tracking Fund.
- Hybrid Index Funds — combine different asset classes, such as stocks and bonds, to create a diversified portfolio that tracks a specific hybrid index, like Vanguard Balanced Index Fund, which tracks the CRSP US Total Market Index for stocks and the Bloomberg Barclays US Aggregate Float Adjusted Index for bonds.
Comparison Table
| Category | Cost | Diversification | Risk |
|---|---|---|---|
| Equity Index Funds | Low, e.g., 0.04% for Vanguard 500 Index Fund (Vanguard) | High, tracking a broad market index like S&P 500 | High, subject to stock market volatility |
| Bond Index Funds | Low, e.g., 0.04% for iShares Core US Aggregate Bond ETF (BlackRock) | Medium, tracking a specific bond market index | Medium, subject to interest rate and credit risk |
| Commodity Index Funds | High, e.g., 0.85% for Invesco DB Commodity Index Tracking Fund (Invesco) | Low, tracking a specific commodity index | High, subject to commodity price volatility |
| Hybrid Index Funds | Medium, e.g., 0.22% for Vanguard Balanced Index Fund (Vanguard) | High, tracking a diversified hybrid index | Medium, subject to both stock and bond market risks |
How They Relate
The categories overlap in that Equity Index Funds and Bond Index Funds are often combined to create Hybrid Index Funds, which aim to balance risk and return by allocating assets across different asset classes. Commodity Index Funds are often used as a hedge against inflation or to diversify a portfolio beyond traditional stocks and bonds. Specifically, Equity Index Funds and Commodity Index Funds are commonly confused due to their high-risk profiles, but they track different underlying markets and have distinct investment characteristics. In contrast, Bond Index Funds and Hybrid Index Funds are often compared due to their focus on income generation, but they differ in their asset allocation and risk profiles.