MRGAX vs. FSKAX

Last updated Jul 17, 2026

MRGAX (MFS Core Equity Fund) and FSKAX (Fidelity Total Market Index Fund) are both Large Cap Blend Equities funds. Over the past 10 years, MRGAX returned 13.95%/yr vs 14.71%/yr for FSKAX. With a 0.98 correlation, they move nearly in lockstep. MRGAX charges 0.93%/yr vs 0.01%/yr for FSKAX.

Performance

MRGAX vs. FSKAX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in MFS Core Equity Fund (MRGAX) and Fidelity Total Market Index Fund (FSKAX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, MRGAX achieves a 8.95% return, which is significantly lower than FSKAX's 11.80% return. Over the past 10 years, MRGAX has underperformed FSKAX with an annualized return of 13.95%, while FSKAX has yielded a comparatively higher 14.71% annualized return.

MRGAX

• 1D: 0.31%
• 1M: 1.57%
• 6M: 6.81%
• YTD: 8.95%
• 1Y: 16.08%
• 3Y*: 16.19%
• 5Y*: 10.17%
• 10Y*: 13.95%

FSKAX

• 1D: 0.35%
• 1M: 0.86%
• 6M: 9.61%
• YTD: 11.80%
• 1Y: 22.51%
• 3Y*: 20.10%
• 5Y*: 12.44%
• 10Y*: 14.71%

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

MRGAX vs. FSKAX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
MRGAX MFS Core Equity Fund	8.95%	12.33%	20.01%	22.88%	-17.24%	25.26%	18.56%	34.66%	-4.12%	23.79%
FSKAX Fidelity Total Market Index Fund	11.80%	17.06%	23.89%	26.12%	-19.53%	25.66%	20.79%	30.92%	-5.32%	20.85%

Correlation

The correlation between MRGAX and FSKAX is 0.97 - 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	0.97
Correlation (3Y) Calculated over the trailing 3-year period	0.98
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 8, 2011	0.98

The correlation between MRGAX and FSKAX has been stable across timeframes, ranging from 0.97 to 0.99 - a consistent structural relationship.

Return for Risk

MRGAX vs. FSKAX — Risk / Return Rank

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

MRGAX

MRGAX Risk / Return Rank: 35
MRGAX Sharpe Ratio Rank: 35
MRGAX Sortino Ratio Rank: 33
MRGAX Omega Ratio Rank: 34
MRGAX Calmar Ratio Rank: 33
MRGAX Martin Ratio Rank: 40

FSKAX

FSKAX Risk / Return Rank: 68
FSKAX Sharpe Ratio Rank: 66
FSKAX Sortino Ratio Rank: 61
FSKAX Omega Ratio Rank: 62
FSKAX Calmar Ratio Rank: 70
FSKAX Martin Ratio Rank: 80

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.

MRGAX vs. FSKAX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for MFS Core Equity Fund (MRGAX) and Fidelity Total Market Index Fund (FSKAX). 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.

Values are calculated on a 1-year rolling basis and updated daily. Risk-adjusted metrics are more stable over longer periods — use the period switch above to explore them.

	MRGAX	FSKAX	Difference
Sharpe ratio: Return per unit of total volatility	1.33	1.79	-0.46
Sortino ratio: Return per unit of downside risk	1.87	2.45	-0.58
Omega ratio: Gain probability vs. loss probability	1.24	1.32	-0.08
Calmar ratio: Return relative to maximum drawdown	1.73	2.59	-0.85
Martin ratio: Return relative to average drawdown	7.03	11.30	-4.27

MRGAX vs. FSKAX - Sharpe Ratio Comparison

The current MRGAX Sharpe Ratio is 1.33, which is comparable to the FSKAX Sharpe Ratio of 1.79. The chart below compares the historical Sharpe Ratios of MRGAX and FSKAX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Drawdowns

MRGAX vs. FSKAX - Drawdown Comparison

The maximum MRGAX drawdown since its inception was -54.04%, which is greater than FSKAX's maximum drawdown of -35.01%. Use the drawdown chart below to compare losses from any high point for MRGAX and FSKAX.

Drawdown Indicators

	MRGAX	FSKAX	Difference
Max Drawdown Largest peak-to-trough decline	-54.04%	-35.01%	-19.03%
Max Drawdown (1Y) Largest decline over 1 year	-9.53%	-8.92%	-0.61%
Max Drawdown (3Y) Largest decline over 3 years	-19.22%	-19.43%	+0.21%
Max Drawdown (5Y) Largest decline over 5 years	-23.08%	-25.39%	+2.31%
Max Drawdown (10Y) Largest decline over 10 years	-33.41%	-35.01%	+1.60%
Current Drawdown Current decline from peak	0.00%	-0.25%	+0.25%
Average Drawdown Average peak-to-trough decline	-8.24%	-4.00%	-4.24%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.35%	2.04%	+0.31%

Volatility

MRGAX vs. FSKAX - Volatility Comparison

MFS Core Equity Fund (MRGAX) and Fidelity Total Market Index Fund (FSKAX) have volatilities of 3.42% and 3.58%, 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

	MRGAX	FSKAX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.42%	3.58%	-0.16%
Volatility (6M) Calculated over the trailing 6-month period	9.87%	10.22%	-0.35%
Volatility (1Y) Calculated over the trailing 1-year period	12.45%	12.93%	-0.48%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	16.87%	17.52%	-0.65%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	17.76%	18.44%	-0.68%

MRGAX vs. FSKAX - Expense Ratio Comparison

MRGAX has a 0.93% expense ratio, which is higher than FSKAX's 0.02% expense ratio.

Dividends

MRGAX vs. FSKAX - Dividend Comparison

MRGAX's dividend yield for the trailing twelve months is around 12.48%, more than FSKAX's 0.93% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FSKAX Fidelity Total Market Index Fund	0.93%	1.01%	1.19%	1.41%	1.62%	1.15%	1.45%	1.94%	2.54%	2.07%	2.43%	0.82%
MRGAX MFS Core Equity Fund	12.48%	13.60%	8.21%	2.54%	3.83%	7.28%	1.54%	3.20%	11.09%	6.27%	3.65%	11.02%

Frequently Asked Questions

Can I hold both MRGAX and FSKAX in my portfolio?

With a correlation of 0.97, MRGAX and FSKAX 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.

Which is riskier, MRGAX or FSKAX?

FSKAX has higher volatility (3.58%) compared to MRGAX (3.42%). In terms of maximum drawdown, MRGAX dropped -54.04% vs FSKAX's -35.01%.

Which has better risk-adjusted returns?

FSKAX currently has the higher Sharpe Ratio (1.79 vs 1.33), 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.