SPFIX vs. WFSPX
SPFIX (Shelton Capital Management S&P 500 Index Fund) and WFSPX (iShares S&P 500 Index Fund) are both S&P 500 funds from BlackRock tracking the S&P 500 Index. Both are passively managed. Over the past 10 years, SPFIX returned 17.69%/yr vs 15.54%/yr for WFSPX. With a 0.99 correlation, they move nearly in lockstep. SPFIX charges 0.43%/yr vs 0.03%/yr for WFSPX.
Performance
SPFIX vs. WFSPX - Performance Comparison
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Returns By Period
The year-to-date returns for both investments are quite close, with SPFIX having a 11.42% return and WFSPX slightly higher at 11.69%. Over the past 10 years, SPFIX has outperformed WFSPX with an annualized return of 17.69%, while WFSPX has yielded a comparatively lower 15.54% annualized return.
SPFIX
- 1D
- 0.14%
- 1M
- 5.71%
- YTD
- 11.42%
- 6M
- 11.42%
- 1Y
- 28.45%
- 3Y*
- 27.82%
- 5Y*
- 16.92%
- 10Y*
- 17.69%
WFSPX
- 1D
- 0.13%
- 1M
- 5.80%
- YTD
- 11.69%
- 6M
- 11.72%
- 1Y
- 28.93%
- 3Y*
- 22.71%
- 5Y*
- 14.24%
- 10Y*
- 15.54%
SPFIX vs. WFSPX - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
SPFIX Shelton Capital Management S&P 500 Index Fund | 11.42% | 17.23% | 42.83% | 25.48% | -18.22% | 27.99% | 17.41% | 41.64% | -4.68% | 21.55% |
WFSPX iShares S&P 500 Index Fund | 11.69% | 17.83% | 24.94% | 26.25% | -18.14% | 28.63% | 18.43% | 31.45% | -4.83% | 21.27% |
Correlation
The correlation between SPFIX and WFSPX is 1.00 - 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 | 1.00 |
Correlation (3Y) Calculated over the trailing 3-year period | 1.00 |
Correlation (5Y) Calculated over the trailing 5-year period | 1.00 |
Correlation (10Y) Calculated over the trailing 10-year period | 0.99 |
Correlation (All Time) Calculated using the full available price history since Jul 6, 1993 | 0.99 |
The correlation between SPFIX and WFSPX has been stable across timeframes, ranging from 0.99 to 1.00 - a consistent structural relationship.
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Return for Risk
SPFIX vs. WFSPX — Risk / Return Rank
SPFIX
WFSPX
SPFIX vs. WFSPX - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for Shelton Capital Management S&P 500 Index Fund (SPFIX) and iShares S&P 500 Index Fund (WFSPX). 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.
| SPFIX | WFSPX | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | -0.03 | ||
| Sortino ratioReturn per unit of downside risk | -0.04 | ||
| Omega ratioGain probability vs. loss probability | 1.45 | 1.46 | -0.01 |
| Calmar ratioReturn relative to maximum drawdown | 3.29 | 3.35 | -0.06 |
| Martin ratioReturn relative to average drawdown | 15.35 | 15.65 | -0.30 |
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
| SPFIX | WFSPX | Difference | |
|---|---|---|---|
Sharpe Ratio (1Y)Calculated over the trailing 1-year period | 2.48 | 2.52 | -0.03 |
Sharpe Ratio (5Y)Calculated over the trailing 5-year period | 0.93 | 0.85 | +0.09 |
Sharpe Ratio (10Y)Calculated over the trailing 10-year period | 0.94 | 0.87 | +0.08 |
Sharpe Ratio (All Time)Calculated using the full available price history | 0.59 | 0.13 | +0.46 |
Drawdowns
SPFIX vs. WFSPX - Drawdown Comparison
The maximum SPFIX drawdown since its inception was -54.81%, smaller than the maximum WFSPX drawdown of -58.21%. Use the drawdown chart below to compare losses from any high point for SPFIX and WFSPX.
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Drawdown Indicators
| SPFIX | WFSPX | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -54.81% | -58.21% | +3.40% |
Max Drawdown (1Y)Largest decline over 1 year | -8.90% | -8.90% | 0.00% |
Max Drawdown (3Y)Largest decline over 3 years | -18.94% | -18.74% | -0.20% |
Max Drawdown (5Y)Largest decline over 5 years | -24.69% | -24.51% | -0.18% |
Max Drawdown (10Y)Largest decline over 10 years | -33.83% | -33.74% | -0.09% |
Current DrawdownCurrent decline from peak | 0.00% | 0.00% | 0.00% |
Average DrawdownAverage peak-to-trough decline | -8.95% | -12.77% | +3.82% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 1.91% | 1.90% | +0.01% |
Volatility
SPFIX vs. WFSPX - Volatility Comparison
Shelton Capital Management S&P 500 Index Fund (SPFIX) and iShares S&P 500 Index Fund (WFSPX) have volatilities of 2.82% and 2.82%, respectively, indicating that both stocks experience similar levels of price fluctuations. This suggests that the risk associated with both stocks, as measured by volatility, is nearly the same. The chart below showcases a comparison of their rolling one-month volatility.
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Volatility by Period
| SPFIX | WFSPX | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 2.82% | 2.82% | 0.00% |
Volatility (6M)Calculated over the trailing 6-month period | 8.93% | 8.97% | -0.04% |
Volatility (1Y)Calculated over the trailing 1-year period | 11.81% | 11.85% | -0.04% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 18.23% | 16.88% | +1.35% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 18.88% | 18.02% | +0.86% |
SPFIX vs. WFSPX - Expense Ratio Comparison
SPFIX has a 0.43% expense ratio, which is higher than WFSPX's 0.03% expense ratio.
Dividends
SPFIX vs. WFSPX - Dividend Comparison
SPFIX's dividend yield for the trailing twelve months is around 3.26%, more than WFSPX's 1.56% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
SPFIX Shelton Capital Management S&P 500 Index Fund | 3.26% | 3.45% | 27.20% | 8.08% | 5.07% | 5.43% | 8.06% | 16.60% | 2.49% | 3.01% | 2.92% | 4.35% |
WFSPX iShares S&P 500 Index Fund | 1.56% | 1.72% | 1.41% | 1.50% | 2.02% | 1.82% | 1.66% | 1.99% | 2.00% | 1.62% | 2.37% | 2.49% |
Frequently Asked Questions
With a correlation of 1.00, SPFIX and WFSPX 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.
WFSPX has higher volatility (2.82%) compared to SPFIX (2.82%). In terms of maximum drawdown, SPFIX dropped -54.81% vs WFSPX's -58.21%.
WFSPX currently has the higher Sharpe Ratio (2.52 vs 2.48), 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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