FSKAX vs. VIIIX
FSKAX (Fidelity Total Market Index Fund) and VIIIX (Vanguard Institutional Index Fund Institutional Plus Shares) are both mutual funds - FSKAX is a Large Cap Blend Equities fund managed by Fidelity, while VIIIX is a S&P 500 fund tracking the S&P 500 Index. Over the past 10 years, FSKAX returned 15.01%/yr vs 15.65%/yr for VIIIX. With a 0.99 correlation, they move nearly in lockstep. FSKAX charges 0.01%/yr vs 0.02%/yr for VIIIX.
Performance
FSKAX vs. VIIIX - Performance Comparison
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Returns By Period
The year-to-date returns for both stocks are quite close, with FSKAX having a 11.22% return and VIIIX slightly lower at 10.88%. Both investments have delivered pretty close results over the past 10 years, with FSKAX having a 15.01% annualized return and VIIIX not far ahead at 15.65%.
FSKAX
- 1D
- -0.77%
- 1M
- 4.09%
- YTD
- 11.22%
- 6M
- 10.94%
- 1Y
- 28.11%
- 3Y*
- 22.10%
- 5Y*
- 12.71%
- 10Y*
- 15.01%
VIIIX
- 1D
- -0.74%
- 1M
- 4.17%
- YTD
- 10.88%
- 6M
- 10.80%
- 1Y
- 28.02%
- 3Y*
- 22.87%
- 5Y*
- 14.05%
- 10Y*
- 15.65%
FSKAX vs. VIIIX - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
FSKAX Fidelity Total Market Index Fund | 11.22% | 17.06% | 23.89% | 26.12% | -19.53% | 25.66% | 20.79% | 30.92% | -5.32% | 20.85% |
VIIIX Vanguard Institutional Index Fund Institutional Plus Shares | 10.88% | 17.87% | 26.29% | 25.79% | -18.14% | 28.69% | 18.41% | 31.48% | -4.41% | 21.82% |
Correlation
The correlation between FSKAX and VIIIX is 0.99 - these two move nearly in lockstep. At this level, holding both provides almost no diversification benefit. If you already own one, adding the other does little to reduce portfolio risk.
| Correlation | |
|---|---|
Correlation (1Y) Calculated over the trailing 1-year period | 0.99 |
Correlation (3Y) Calculated over the trailing 3-year period | 0.99 |
Correlation (5Y) Calculated over the trailing 5-year period | 0.99 |
Correlation (10Y) Calculated over the trailing 10-year period | 0.99 |
Correlation (All Time) Calculated using the full available price history since Sep 9, 2011 | 0.99 |
The correlation between FSKAX and VIIIX has been stable across timeframes, ranging from 0.99 to 0.99 - a consistent structural relationship.
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Return for Risk
FSKAX vs. VIIIX — Risk / Return Rank
FSKAX
VIIIX
FSKAX vs. VIIIX - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for Fidelity Total Market Index Fund (FSKAX) and Vanguard Institutional Index Fund Institutional Plus Shares (VIIIX). Risk-adjusted metrics are performance indicators that assess an investment's returns in relation to its risk, enabling a more accurate comparison of different investment options.
| FSKAX | VIIIX | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | -0.07 | ||
| Sortino ratioReturn per unit of downside risk | -0.09 | ||
| Omega ratioGain probability vs. loss probability | 1.41 | 1.43 | -0.02 |
| Calmar ratioReturn relative to maximum drawdown | 3.17 | 3.17 | 0.00 |
| Martin ratioReturn relative to average drawdown | 14.55 | 14.79 | -0.25 |
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month. | |||
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Sharpe Ratios by Period
| FSKAX | VIIIX | Difference | |
|---|---|---|---|
Sharpe Ratio (1Y)Calculated over the trailing 1-year period | 2.30 | 2.37 | -0.07 |
Sharpe Ratio (5Y)Calculated over the trailing 5-year period | 0.73 | 0.84 | -0.10 |
Sharpe Ratio (10Y)Calculated over the trailing 10-year period | 0.82 | 0.87 | -0.05 |
Sharpe Ratio (All Time)Calculated using the full available price history | 0.85 | 0.49 | +0.35 |
Drawdowns
FSKAX vs. VIIIX - Drawdown Comparison
The maximum FSKAX drawdown since its inception was -35.01%, smaller than the maximum VIIIX drawdown of -55.18%. Use the drawdown chart below to compare losses from any high point for FSKAX and VIIIX.
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Drawdown Indicators
| FSKAX | VIIIX | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -35.01% | -55.18% | +20.17% |
Max Drawdown (1Y)Largest decline over 1 year | -8.92% | -8.90% | -0.02% |
Max Drawdown (3Y)Largest decline over 3 years | -19.43% | -18.75% | -0.68% |
Max Drawdown (5Y)Largest decline over 5 years | -25.39% | -24.50% | -0.89% |
Max Drawdown (10Y)Largest decline over 10 years | -35.01% | -33.79% | -1.22% |
Current DrawdownCurrent decline from peak | -0.77% | -0.74% | -0.03% |
Average DrawdownAverage peak-to-trough decline | -4.02% | -10.02% | +6.00% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 1.94% | 1.90% | +0.04% |
Volatility
FSKAX vs. VIIIX - Volatility Comparison
Fidelity Total Market Index Fund (FSKAX) has a higher volatility of 3.08% compared to Vanguard Institutional Index Fund Institutional Plus Shares (VIIIX) at 2.93%. This indicates that FSKAX's price experiences larger fluctuations and is considered to be riskier than VIIIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.
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Volatility by Period
| FSKAX | VIIIX | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 3.08% | 2.93% | +0.15% |
Volatility (6M)Calculated over the trailing 6-month period | 9.25% | 8.99% | +0.26% |
Volatility (1Y)Calculated over the trailing 1-year period | 12.29% | 11.88% | +0.41% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 17.41% | 16.89% | +0.52% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 18.46% | 18.06% | +0.40% |
FSKAX vs. VIIIX - Expense Ratio Comparison
FSKAX has a 0.02% expense ratio, which is lower than VIIIX's 0.02% expense ratio. Despite the difference, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.
Dividends
FSKAX vs. VIIIX - Dividend Comparison
FSKAX's dividend yield for the trailing twelve months is around 0.94%, less than VIIIX's 2.43% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
FSKAX Fidelity Total Market Index Fund | 0.94% | 1.01% | 1.19% | 1.41% | 1.62% | 1.15% | 1.45% | 1.94% | 2.54% | 2.07% | 2.43% | 0.82% |
VIIIX Vanguard Institutional Index Fund Institutional Plus Shares | 2.43% | 2.11% | 3.66% | 2.66% | 3.39% | 4.79% | 3.07% | 2.86% | 2.45% | 1.84% | 2.38% | 2.47% |
Frequently Asked Questions
With a correlation of 0.99, FSKAX and VIIIX move almost identically. Holding both adds very little diversification - you're essentially doubling your position in the same market segment. Choosing one is usually more capital-efficient.
FSKAX has higher volatility (3.08%) compared to VIIIX (2.93%). In terms of maximum drawdown, FSKAX dropped -35.01% vs VIIIX's -55.18%.
VIIIX currently has the higher Sharpe Ratio (2.37 vs 2.30), meaning it's delivered slightly more return per unit of risk over the trailing 12 months. However, this ranking shifts over time - use the Risk/Return Score above for a more comprehensive view that combines Sharpe, Sortino, and other measures used by quantitative funds.
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