MFEIX vs. RYGRX

Last updated Jun 3, 2026

MFEIX (MFS Growth I) and RYGRX (Rydex S&P 500 Pure Growth Fund) are both Large Cap Growth Equities funds. Over the past 10 years, MFEIX returned 17.71%/yr vs 13.09%/yr for RYGRX. Their correlation of 0.92 suggests significant overlap in exposure. MFEIX charges 0.60%/yr vs 2.26%/yr for RYGRX.

Performance

MFEIX vs. RYGRX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in MFS Growth I (MFEIX) and Rydex S&P 500 Pure Growth Fund (RYGRX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, MFEIX achieves a 6.65% return, which is significantly lower than RYGRX's 28.96% return. Over the past 10 years, MFEIX has outperformed RYGRX with an annualized return of 17.71%, while RYGRX has yielded a comparatively lower 13.09% annualized return.

MFEIX

• 1D: 1.14%
• 1M: 4.91%
• YTD: 6.65%
• 6M: 5.81%
• 1Y: 18.57%
• 3Y*: 26.76%
• 5Y*: 14.29%
• 10Y*: 17.71%

RYGRX

• 1D: 0.92%
• 1M: 10.41%
• YTD: 28.96%
• 6M: 30.49%
• 1Y: 38.01%
• 3Y*: 25.29%
• 5Y*: 10.65%
• 10Y*: 13.09%

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

MFEIX vs. RYGRX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
MFEIX MFS Growth I	6.65%	12.34%	49.67%	36.15%	-31.14%	23.59%	31.65%	37.69%	2.30%	30.86%
RYGRX Rydex S&P 500 Pure Growth Fund	28.96%	11.00%	25.73%	5.80%	-28.71%	26.61%	26.34%	34.13%	-6.28%	23.74%

Correlation

The correlation between MFEIX and RYGRX is 0.78, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.78
Correlation (3Y) Calculated over the trailing 3-year period	0.79
Correlation (5Y) Calculated over the trailing 5-year period	0.85
Correlation (10Y) Calculated over the trailing 10-year period	0.88
Correlation (All Time) Calculated using the full available price history since Jan 4, 2005	0.92

The correlation between MFEIX and RYGRX shifts across timeframes, from 0.78 (1 year) to 0.92 (all time), reflecting how their relationship changes across market environments.

Return for Risk

MFEIX vs. RYGRX — Risk / Return Rank

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

MFEIX

MFEIX Risk / Return Rank: 14
MFEIX Sharpe Ratio Rank: 17
MFEIX Sortino Ratio Rank: 16
MFEIX Omega Ratio Rank: 16
MFEIX Calmar Ratio Rank: 11
MFEIX Martin Ratio Rank: 12

RYGRX

RYGRX Risk / Return Rank: 55
RYGRX Sharpe Ratio Rank: 45
RYGRX Sortino Ratio Rank: 41
RYGRX Omega Ratio Rank: 40
RYGRX Calmar Ratio Rank: 78
RYGRX Martin Ratio Rank: 70

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.

MFEIX vs. RYGRX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for MFS Growth I (MFEIX) and Rydex S&P 500 Pure Growth Fund (RYGRX). 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.

	MFEIX	RYGRX	Difference
Sharpe ratio Return per unit of total volatility	1.23	1.98	-0.75
Sortino ratio Return per unit of downside risk	1.72	2.68	-0.95
Omega ratio Gain probability vs. loss probability	1.22	1.34	-0.12
Calmar ratio Return relative to maximum drawdown	1.13	3.52	-2.39
Martin ratio Return relative to average drawdown	3.67	13.52	-9.85
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

MFEIX vs. RYGRX - Sharpe Ratio Comparison

The current MFEIX Sharpe Ratio is 1.23, which is lower than the RYGRX Sharpe Ratio of 1.98. The chart below compares the historical Sharpe Ratios of MFEIX and RYGRX, 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

	MFEIX	RYGRX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.23	1.98	-0.75
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.66	0.46	+0.20
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.84	0.57	+0.26
Sharpe Ratio (All Time) Calculated using the full available price history	0.44	0.44	+0.01

Drawdowns

MFEIX vs. RYGRX - Drawdown Comparison

The maximum MFEIX drawdown since its inception was -72.24%, which is greater than RYGRX's maximum drawdown of -54.22%. Use the drawdown chart below to compare losses from any high point for MFEIX and RYGRX.

Drawdown Indicators

	MFEIX	RYGRX	Difference
Max Drawdown Largest peak-to-trough decline	-72.24%	-54.22%	-18.02%
Max Drawdown (1Y) Largest decline over 1 year	-17.30%	-11.17%	-6.13%
Max Drawdown (3Y) Largest decline over 3 years	-23.24%	-24.95%	+1.71%
Max Drawdown (5Y) Largest decline over 5 years	-36.11%	-36.57%	+0.46%
Max Drawdown (10Y) Largest decline over 10 years	-36.11%	-36.63%	+0.52%
Current Drawdown Current decline from peak	0.00%	0.00%	0.00%
Average Drawdown Average peak-to-trough decline	-23.73%	-9.41%	-14.32%
Ulcer Index Depth and duration of drawdowns from previous peaks	5.31%	2.91%	+2.40%

Volatility

MFEIX vs. RYGRX - Volatility Comparison

The current volatility for MFS Growth I (MFEIX) is 3.55%, while Rydex S&P 500 Pure Growth Fund (RYGRX) has a volatility of 6.39%. This indicates that MFEIX experiences smaller price fluctuations and is considered to be less risky than RYGRX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	MFEIX	RYGRX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.55%	6.39%	-2.84%
Volatility (6M) Calculated over the trailing 6-month period	12.25%	16.29%	-4.04%
Volatility (1Y) Calculated over the trailing 1-year period	15.86%	19.74%	-3.88%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	21.90%	23.50%	-1.60%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	21.24%	22.88%	-1.64%

MFEIX vs. RYGRX - Expense Ratio Comparison

MFEIX has a 0.60% expense ratio, which is lower than RYGRX's 2.26% expense ratio.

Dividends

MFEIX vs. RYGRX - Dividend Comparison

MFEIX's dividend yield for the trailing twelve months is around 14.06%, more than RYGRX's 3.95% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
MFEIX MFS Growth I	14.06%	14.99%	25.47%	4.86%	1.05%	2.76%	3.57%	1.57%	3.78%	2.50%	1.61%	3.65%
RYGRX Rydex S&P 500 Pure Growth Fund	3.95%	5.09%	0.00%	0.00%	0.00%	2.81%	4.43%	12.10%	7.15%	6.26%	0.05%	2.96%

Frequently Asked Questions

Can I hold both MFEIX and RYGRX in my portfolio?

MFEIX and RYGRX have a correlation of 0.78, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, MFEIX or RYGRX?

RYGRX has higher volatility (6.39%) compared to MFEIX (3.55%). In terms of maximum drawdown, MFEIX dropped -72.24% vs RYGRX's -54.22%.

Which has better risk-adjusted returns?

RYGRX currently has the higher Sharpe Ratio (1.98 vs 1.23), 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.