MRSIX vs. FSPSX

Last updated Jun 24, 2026

MRSIX (MFS Research International Fund) and FSPSX (Fidelity International Index Fund) are both Foreign Large Cap Equities funds. Over the past 10 years, MRSIX returned 9.53%/yr vs 10.29%/yr for FSPSX. With a 0.96 correlation, they move nearly in lockstep. MRSIX charges 0.76%/yr vs 0.04%/yr for FSPSX.

Performance

MRSIX vs. FSPSX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in MFS Research International Fund (MRSIX) and Fidelity International Index Fund (FSPSX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

The year-to-date returns for both investments are quite close, with MRSIX having a 10.64% return and FSPSX slightly higher at 10.74%. Over the past 10 years, MRSIX has underperformed FSPSX with an annualized return of 9.53%, while FSPSX has yielded a comparatively higher 10.29% annualized return.

MRSIX

• 1D: 0.00%
• 1M: 2.46%
• YTD: 10.64%
• 6M: 10.35%
• 1Y: 20.07%
• 3Y*: 13.61%
• 5Y*: 6.35%
• 10Y*: 9.53%

FSPSX

• 1D: 0.18%
• 1M: 2.11%
• YTD: 10.74%
• 6M: 10.40%
• 1Y: 24.77%
• 3Y*: 17.73%
• 5Y*: 9.39%
• 10Y*: 10.29%

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

MRSIX vs. FSPSX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
MRSIX MFS Research International Fund	10.64%	22.61%	3.06%	13.44%	-17.33%	11.87%	13.18%	27.98%	-13.98%	28.38%
FSPSX Fidelity International Index Fund	10.74%	31.98%	3.70%	18.31%	-14.23%	11.45%	8.16%	22.03%	-13.55%	25.37%

Correlation

The correlation between MRSIX and FSPSX is 0.94, 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	0.94
Correlation (3Y) Calculated over the trailing 3-year period	0.95
Correlation (5Y) Calculated over the trailing 5-year period	0.97
Correlation (10Y) Calculated over the trailing 10-year period	0.96
Correlation (All Time) Calculated using the full available price history since Sep 8, 2011	0.96

The correlation between MRSIX and FSPSX has been stable across timeframes, ranging from 0.94 to 0.96 - a consistent structural relationship.

Return for Risk

MRSIX vs. FSPSX — Risk / Return Rank

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

MRSIX

MRSIX Risk / Return Rank: 29
MRSIX Sharpe Ratio Rank: 31
MRSIX Sortino Ratio Rank: 31
MRSIX Omega Ratio Rank: 32
MRSIX Calmar Ratio Rank: 26
MRSIX Martin Ratio Rank: 28

FSPSX

FSPSX Risk / Return Rank: 39
FSPSX Sharpe Ratio Rank: 40
FSPSX Sortino Ratio Rank: 38
FSPSX Omega Ratio Rank: 38
FSPSX Calmar Ratio Rank: 39
FSPSX Martin Ratio Rank: 42

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.

MRSIX vs. FSPSX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for MFS Research International Fund (MRSIX) and Fidelity International Index Fund (FSPSX). 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.

	MRSIX	FSPSX	Difference
Sharpe ratio: Return per unit of total volatility	1.49	1.69	-0.21
Sortino ratio: Return per unit of downside risk	2.14	2.39	-0.25
Omega ratio: Gain probability vs. loss probability	1.27	1.31	-0.03
Calmar ratio: Return relative to maximum drawdown	1.76	2.26	-0.51
Martin ratio: Return relative to average drawdown	6.06	8.48	-2.41

MRSIX vs. FSPSX - Sharpe Ratio Comparison

The current MRSIX Sharpe Ratio is 1.49, which is comparable to the FSPSX Sharpe Ratio of 1.69. The chart below compares the historical Sharpe Ratios of MRSIX and FSPSX, 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

MRSIX vs. FSPSX - Drawdown Comparison

The maximum MRSIX drawdown since its inception was -59.56%, which is greater than FSPSX's maximum drawdown of -33.69%. Use the drawdown chart below to compare losses from any high point for MRSIX and FSPSX.

Drawdown Indicators

	MRSIX	FSPSX	Difference
Max Drawdown Largest peak-to-trough decline	-59.56%	-33.69%	-25.87%
Max Drawdown (1Y) Largest decline over 1 year	-11.64%	-11.39%	-0.25%
Max Drawdown (3Y) Largest decline over 3 years	-13.95%	-13.58%	-0.37%
Max Drawdown (5Y) Largest decline over 5 years	-30.73%	-29.41%	-1.32%
Max Drawdown (10Y) Largest decline over 10 years	-30.73%	-33.69%	+2.96%
Current Drawdown Current decline from peak	-0.33%	0.00%	-0.33%
Average Drawdown Average peak-to-trough decline	-12.73%	-6.53%	-6.20%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.36%	3.04%	+0.32%

Volatility

MRSIX vs. FSPSX - Volatility Comparison

MFS Research International Fund (MRSIX) and Fidelity International Index Fund (FSPSX) have volatilities of 4.59% and 4.77%, 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

	MRSIX	FSPSX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.59%	4.77%	-0.18%
Volatility (6M) Calculated over the trailing 6-month period	11.32%	12.68%	-1.36%
Volatility (1Y) Calculated over the trailing 1-year period	13.76%	15.26%	-1.50%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	15.02%	16.07%	-1.05%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	15.44%	16.53%	-1.09%

MRSIX vs. FSPSX - Expense Ratio Comparison

MRSIX has a 0.76% expense ratio, which is higher than FSPSX's 0.04% expense ratio.

Dividends

MRSIX vs. FSPSX - Dividend Comparison

MRSIX's dividend yield for the trailing twelve months is around 4.75%, more than FSPSX's 2.85% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FSPSX Fidelity International Index Fund	2.85%	3.15%	3.27%	2.79%	2.66%	3.07%	1.84%	3.18%	2.79%	2.50%	3.08%	2.79%
MRSIX MFS Research International Fund	4.75%	5.26%	2.00%	1.67%	1.57%	1.29%	0.92%	1.79%	5.48%	1.21%	1.97%	1.89%

Frequently Asked Questions

Can I hold both MRSIX and FSPSX in my portfolio?

With a correlation of 0.94, MRSIX and FSPSX 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, MRSIX or FSPSX?

FSPSX has higher volatility (4.77%) compared to MRSIX (4.59%). In terms of maximum drawdown, MRSIX dropped -59.56% vs FSPSX's -33.69%.

Which has better risk-adjusted returns?

FSPSX currently has the higher Sharpe Ratio (1.69 vs 1.49), 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.