MIGNX vs. WFSPX

Last updated Apr 1, 2026

Compare and contrast key facts about MFS Massachusetts Investors Growth Stock Fund Class R6 (MIGNX) and iShares S&P 500 Index Fund (WFSPX).

MIGNX is a passively managed fund by MFS that tracks the performance of the Russell 1000 Growth Index. It was launched on Jun 1, 2012. WFSPX is a passively managed fund by BlackRock that tracks the performance of the S&P 500 Index. It was launched on Jul 30, 1993. Both MIGNX and WFSPX are passive ETFs, meaning that they are not actively managed but aim to replicate the performance of the underlying index as closely as possible.

Performance

MIGNX vs. WFSPX - Performance Comparison

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

MIGNX vs. WFSPX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
MIGNX MFS Massachusetts Investors Growth Stock Fund Class R6	-11.85%	10.31%	27.60%	24.51%	-18.92%	26.52%	22.96%	40.34%	1.14%	29.12%
WFSPX iShares S&P 500 Index Fund	-7.06%	17.83%	24.94%	26.25%	-18.14%	28.63%	18.43%	31.45%	-4.83%	21.27%

Returns By Period

In the year-to-date period, MIGNX achieves a -11.85% return, which is significantly lower than WFSPX's -7.06% return. Both investments have delivered pretty close results over the past 10 years, with MIGNX having a 13.69% annualized return and WFSPX not far behind at 13.63%.

MIGNX

• 1D: -0.21%
• 1M: -9.00%
• YTD: -11.85%
• 6M: -10.61%
• 1Y: 2.43%
• 3Y*: 12.73%
• 5Y*: 8.87%
• 10Y*: 13.69%

WFSPX

• 1D: -0.39%
• 1M: -7.68%
• YTD: -7.06%
• 6M: -4.63%
• 1Y: 14.40%
• 3Y*: 17.13%
• 5Y*: 11.37%
• 10Y*: 13.63%

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

MIGNX vs. WFSPX - Expense Ratio Comparison

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

MIGNX

MFS Massachusetts Investors Growth Stock Fund Class R6

WFSPX

iShares S&P 500 Index Fund

Return for Risk

MIGNX vs. WFSPX — Risk / Return Rank

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

MIGNX

MIGNX Risk / Return Rank: 8
MIGNX Sharpe Ratio Rank: 9
MIGNX Sortino Ratio Rank: 9
MIGNX Omega Ratio Rank: 9
MIGNX Calmar Ratio Rank: 7
MIGNX Martin Ratio Rank: 7

WFSPX

WFSPX Risk / Return Rank: 46
WFSPX Sharpe Ratio Rank: 41
WFSPX Sortino Ratio Rank: 45
WFSPX Omega Ratio Rank: 50
WFSPX Calmar Ratio Rank: 41
WFSPX Martin Ratio Rank: 53

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.

MIGNX vs. WFSPX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for MFS Massachusetts Investors Growth Stock Fund Class R6 (MIGNX) 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.

	MIGNX	WFSPX	Difference
Sharpe ratio Return per unit of total volatility	0.16	0.84	-0.68
Sortino ratio Return per unit of downside risk	0.36	1.30	-0.94
Omega ratio Gain probability vs. loss probability	1.05	1.20	-0.15
Calmar ratio Return relative to maximum drawdown	0.07	1.06	-0.99
Martin ratio Return relative to average drawdown	0.24	5.13	-4.89
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

MIGNX vs. WFSPX - Sharpe Ratio Comparison

The current MIGNX Sharpe Ratio is 0.16, which is lower than the WFSPX Sharpe Ratio of 0.84. The chart below compares the historical Sharpe Ratios of MIGNX and WFSPX, offering insights into how both investments have performed under varying market conditions. These values are calculated using daily returns over the previous 12 months.

Sharpe Ratios by Period

	MIGNX	WFSPX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.16	0.84	-0.68
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.51	0.68	-0.17
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.76	0.76	0.00
Sharpe Ratio (All Time) Calculated using the full available price history	0.83	0.13	+0.70

Correlation

The correlation between MIGNX and WFSPX is 0.95, which is considered to be high. That indicates a strong positive relationship between their price movements. Having highly-correlated positions in a portfolio may signal a lack of diversification, potentially leading to increased risk during market downturns.

Dividends

MIGNX vs. WFSPX - Dividend Comparison

MIGNX's dividend yield for the trailing twelve months is around 12.65%, more than WFSPX's 1.58% yield.

	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
MIGNX MFS Massachusetts Investors Growth Stock Fund Class R6	12.65%	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	1.58%	1.72%	1.41%	1.50%	2.02%	1.82%	1.66%	1.99%	2.00%	1.62%	2.37%	2.49%

Drawdowns

MIGNX vs. WFSPX - Drawdown Comparison

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

Drawdown Indicators

	MIGNX	WFSPX	Difference
Max Drawdown Largest peak-to-trough decline	-32.40%	-58.21%	+25.81%
Max Drawdown (1Y) Largest decline over 1 year	-13.68%	-12.11%	-1.57%
Max Drawdown (5Y) Largest decline over 5 years	-26.48%	-24.51%	-1.97%
Max Drawdown (10Y) Largest decline over 10 years	-32.40%	-33.74%	+1.34%
Current Drawdown Current decline from peak	-13.68%	-8.90%	-4.78%
Average Drawdown Average peak-to-trough decline	-3.87%	-12.84%	+8.97%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.74%	2.49%	+1.25%

Volatility

MIGNX vs. WFSPX - Volatility Comparison

MFS Massachusetts Investors Growth Stock Fund Class R6 (MIGNX) and iShares S&P 500 Index Fund (WFSPX) have volatilities of 4.33% and 4.24%, 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.

Volatility by Period

	MIGNX	WFSPX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.33%	4.24%	+0.09%
Volatility (6M) Calculated over the trailing 6-month period	9.34%	9.08%	+0.26%
Volatility (1Y) Calculated over the trailing 1-year period	17.63%	18.06%	-0.43%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	17.44%	16.84%	+0.60%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.16%	17.98%	+0.18%