The Vanguard S&P 500 Index mutual fund (VFIAX) and the Vanguard Total Stock Market Index fund (VTSAX) are two of the largest mutual funds in existence. VFIAX and VTSAX are the core of many investor portfolios. Many investors compare VTSAX vs VFIAX in order to decide which should be the foundation of their portfolio.
The Short Answer
The main difference between VFIAX and VTSAX is that VFIAX is a large- and mid-cap fund, while VTSAX is a total market fund. Despite these differences, the total return between these two funds is nearly identical and I consider them interchangeable.
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The Long Answer
Historical Performance: VTSAX vs VFIAX
Both VTSAX and VFIAX were launched on November 13, 2000. Since then VTSAX has outperformed by about .31% annually. This is most likely driven by small-caps’ relative outperformance initially, even though that trend has reversed during the past decade. Despite variations in the size factor performance over the decades, the long-term performance between these two funds is incredibly similar.
Differences between VTSAX vs VFIAX
The biggest difference between VFIAX and VTSAX is the market cap exposure of the funds. VFIAX tracks the S&P 500 index which includes mostly large-caps and some mid-caps, while VTSAX covers much more of the market by including more mid-caps and small-caps.
Geographic Exposure
Both VFIAX and VTSAX hold essentially 100% stocks, so I will not dig into country exposures or market classification here. For intents and purposes, the two funds have identical exposures.
Market Cap Exposure
VFIAX focuses on the S&P 500 index and so it mostly holds large-caps with a bit of mid-cap exposure. VTSAX tracks the broader CRSP US Total Market Index and so it owns many more mid-caps and small-caps, as of 10/31/2022. In other words, VFIAX is a large-cap vehicle, while VTSAX is a total market vehicle. That being said, due to market cap weighting, both funds are overwhelmingly influenced by the large-cap holdings.
| VFIAX | VTSAX | |
| Large-Cap | 84% | 73% |
| Mid-Cap | 17% | 19% |
| Small-Cap | 0% | 9% |
Sector Weights
The sector weights between VFIAX and VTSAX are nearly identical, as of 10/31/2022. The weights are within 1% for every single sector.
| VFIAX | VTSAX | |
| Basic Materials | 2.27% | 2.51% |
| Consumer Cyclical | 10.59% | 10.66% |
| Financial Services | 13.61% | 13.79% |
| Real Estate | 2.74% | 3.45% |
| Communication Services | 7.36% | 6.80% |
| Energy | 5.37% | 5.31% |
| Industrials | 8.69% | 9.64% |
| Technology | 23.60% | 23.06% |
| Consumer Defensive | 7.38% | 6.75% |
| Healthcare | 15.42% | 15.17% |
| Utilities | 2.97% | 2.87% |
Final Thoughts: VTSAX vs VFIAX
Both VFIAX and VTSAX are large, core funds sponsored and managed by Vanguard. Although VFIAX is more of a large-cap fund and VTSAX is a total market mutual fund, performance has been nearly identical. I view these two funds as essentially interchangeable and would not spend too much energy splitting hairs to decide which one is “better.”
