WFSPX vs. MIGNX

Last updated Jun 3, 2026

WFSPX (iShares S&P 500 Index Fund) and MIGNX (MFS Massachusetts Investors Growth Stock Fund Class R6) are both mutual funds - WFSPX is a S&P 500 fund tracking the S&P 500 Index, while MIGNX is a Large Cap Growth Equities fund tracking the Russell 1000 Growth Index. Both are passively managed. Over the past 10 years, WFSPX returned 15.53%/yr vs 15.05%/yr for MIGNX. Their correlation of 0.94 suggests significant overlap in exposure. WFSPX charges 0.03%/yr vs 0.37%/yr for MIGNX.

Performance

WFSPX vs. MIGNX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in iShares S&P 500 Index Fund (WFSPX) and MFS Massachusetts Investors Growth Stock Fund Class R6 (MIGNX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, WFSPX achieves a 11.54% return, which is significantly higher than MIGNX's 0.43% return. Both investments have delivered pretty close results over the past 10 years, with WFSPX having a 15.53% annualized return and MIGNX not far behind at 15.05%.

WFSPX

• 1D: 0.27%
• 1M: 5.23%
• YTD: 11.54%
• 6M: 11.91%
• 1Y: 29.51%
• 3Y*: 22.66%
• 5Y*: 14.13%
• 10Y*: 15.53%

MIGNX

• 1D: 0.94%
• 1M: 3.17%
• YTD: 0.43%
• 6M: 0.75%
• 1Y: 11.52%
• 3Y*: 16.24%
• 5Y*: 10.47%
• 10Y*: 15.05%

*Multi-year figures are annualized to reflect compound growth (CAGR)

WFSPX vs. MIGNX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
WFSPX iShares S&P 500 Index Fund	11.54%	17.83%	24.94%	26.25%	-18.14%	28.63%	18.43%	31.45%	-4.83%	21.27%
MIGNX MFS Massachusetts Investors Growth Stock Fund Class R6	0.43%	10.31%	27.60%	24.51%	-18.92%	26.52%	22.96%	40.34%	1.14%	29.12%

Correlation

The correlation between WFSPX and MIGNX is 0.90, indicating a strong positive relationship between their price movements. Combining them offers limited diversification - they tend to fall together during downturns.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.90
Correlation (3Y) Calculated over the trailing 3-year period	0.92
Correlation (5Y) Calculated over the trailing 5-year period	0.94
Correlation (10Y) Calculated over the trailing 10-year period	0.94
Correlation (All Time) Calculated using the full available price history since Jun 4, 2012	0.94

The correlation between WFSPX and MIGNX has been stable across timeframes, ranging from 0.90 to 0.94 - a consistent structural relationship.

Return for Risk

WFSPX vs. MIGNX — Risk / Return Rank

Compare risk-adjusted metric ranks to identify better-performing investments over the past 12 months.

WFSPX

WFSPX Risk / Return Rank: 74
WFSPX Sharpe Ratio Rank: 77
WFSPX Sortino Ratio Rank: 69
WFSPX Omega Ratio Rank: 69
WFSPX Calmar Ratio Rank: 74
WFSPX Martin Ratio Rank: 83

MIGNX

MIGNX Risk / Return Rank: 10
MIGNX Sharpe Ratio Rank: 11
MIGNX Sortino Ratio Rank: 11
MIGNX Omega Ratio Rank: 11
MIGNX Calmar Ratio Rank: 8
MIGNX Martin Ratio Rank: 9

The rank (0–100) shows how this investment's returns compare to the risk taken. Higher = better. Based on the past 12 months of data, combining Sharpe, Sortino, and other metrics used by quantitative funds and institutional investors.

WFSPX vs. MIGNX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for iShares S&P 500 Index Fund (WFSPX) and MFS Massachusetts Investors Growth Stock Fund Class R6 (MIGNX). 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.

	WFSPX	MIGNX	Difference
Sharpe ratio Return per unit of total volatility	2.55	0.91	+1.63
Sortino ratio Return per unit of downside risk	3.46	1.34	+2.12
Omega ratio Gain probability vs. loss probability	1.46	1.16	+0.30
Calmar ratio Return relative to maximum drawdown	3.38	0.83	+2.55
Martin ratio Return relative to average drawdown	15.81	2.79	+13.02
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

WFSPX vs. MIGNX - Sharpe Ratio Comparison

The current WFSPX Sharpe Ratio is 2.55, which is higher than the MIGNX Sharpe Ratio of 0.91. The chart below compares the historical Sharpe Ratios of WFSPX and MIGNX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Sharpe Ratios by Period

	WFSPX	MIGNX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.55	0.91	+1.63
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.84	0.60	+0.24
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.86	0.83	+0.03
Sharpe Ratio (All Time) Calculated using the full available price history	0.13	0.89	-0.75

Drawdowns

WFSPX vs. MIGNX - Drawdown Comparison

The maximum WFSPX drawdown since its inception was -58.21%, which is greater than MIGNX's maximum drawdown of -32.40%. Use the drawdown chart below to compare losses from any high point for WFSPX and MIGNX.

Drawdown Indicators

	WFSPX	MIGNX	Difference
Max Drawdown Largest peak-to-trough decline	-58.21%	-32.40%	-25.81%
Max Drawdown (1Y) Largest decline over 1 year	-8.90%	-13.68%	+4.78%
Max Drawdown (3Y) Largest decline over 3 years	-18.74%	-18.63%	-0.11%
Max Drawdown (5Y) Largest decline over 5 years	-24.51%	-26.48%	+1.97%
Max Drawdown (10Y) Largest decline over 10 years	-33.74%	-32.40%	-1.34%
Current Drawdown Current decline from peak	0.00%	-1.65%	+1.65%
Average Drawdown Average peak-to-trough decline	-12.78%	-3.89%	-8.89%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.90%	4.06%	-2.16%

Volatility

WFSPX vs. MIGNX - Volatility Comparison

The current volatility for iShares S&P 500 Index Fund (WFSPX) is 2.82%, while MFS Massachusetts Investors Growth Stock Fund Class R6 (MIGNX) has a volatility of 3.32%. This indicates that WFSPX experiences smaller price fluctuations and is considered to be less risky than MIGNX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	WFSPX	MIGNX	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.82%	3.32%	-0.50%
Volatility (6M) Calculated over the trailing 6-month period	8.98%	9.78%	-0.80%
Volatility (1Y) Calculated over the trailing 1-year period	11.88%	12.65%	-0.77%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	16.88%	17.51%	-0.63%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.02%	18.21%	-0.19%

WFSPX vs. MIGNX - Expense Ratio Comparison

WFSPX has a 0.03% expense ratio, which is lower than MIGNX's 0.37% expense ratio.

Dividends

WFSPX vs. MIGNX - Dividend Comparison

WFSPX's dividend yield for the trailing twelve months is around 1.57%, less than MIGNX's 11.10% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
MIGNX MFS Massachusetts Investors Growth Stock Fund Class R6	11.10%	11.15%	16.98%	4.25%	4.67%	10.36%	7.48%	7.46%	10.83%	7.02%	4.99%	6.73%
WFSPX iShares S&P 500 Index Fund	1.57%	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

Can I hold both WFSPX and MIGNX in my portfolio?

WFSPX and MIGNX have a correlation of 0.90, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, WFSPX or MIGNX?

MIGNX has higher volatility (3.32%) compared to WFSPX (2.82%). In terms of maximum drawdown, WFSPX dropped -58.21% vs MIGNX's -32.40%.

Which has better risk-adjusted returns?

WFSPX currently has the higher Sharpe Ratio (2.55 vs 0.91), 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.