MIDLX vs. COIIX

Last updated Jun 4, 2026

MIDLX (MFS International New Discovery Fund Class R6) and COIIX (Calvert International Opportunities Fund) are both Foreign Small & Mid Cap Equities funds. Over the past 10 years, MIDLX returned 6.86%/yr vs 6.51%/yr for COIIX. Their correlation of 0.90 suggests significant overlap in exposure. MIDLX charges 0.91%/yr vs 1.06%/yr for COIIX.

Performance

MIDLX vs. COIIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in MFS International New Discovery Fund Class R6 (MIDLX) and Calvert International Opportunities Fund (COIIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, MIDLX achieves a 6.95% return, which is significantly higher than COIIX's 6.38% return. Over the past 10 years, MIDLX has outperformed COIIX with an annualized return of 6.86%, while COIIX has yielded a comparatively lower 6.51% annualized return.

MIDLX

• 1D: -0.11%
• 1M: 2.42%
• YTD: 6.95%
• 6M: 7.96%
• 1Y: 11.35%
• 3Y*: 11.09%
• 5Y*: 3.62%
• 10Y*: 6.86%

COIIX

• 1D: 0.00%
• 1M: 2.54%
• YTD: 6.38%
• 6M: 7.98%
• 1Y: 8.04%
• 3Y*: 8.19%
• 5Y*: 0.47%
• 10Y*: 6.51%

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

MIDLX vs. COIIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
MIDLX MFS International New Discovery Fund Class R6	6.95%	17.03%	3.33%	13.21%	-18.52%	5.17%	10.15%	24.97%	-10.29%	30.65%
COIIX Calvert International Opportunities Fund	6.38%	13.80%	-1.48%	12.95%	-26.69%	13.97%	14.05%	26.09%	-14.57%	38.55%

Correlation

The correlation between MIDLX and COIIX is 0.91, 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	0.91
Correlation (3Y) Calculated over the trailing 3-year period	0.91
Correlation (5Y) Calculated over the trailing 5-year period	0.93
Correlation (10Y) Calculated over the trailing 10-year period	0.92
Correlation (All Time) Calculated using the full available price history since Jun 4, 2012	0.90

The correlation between MIDLX and COIIX has been stable across timeframes, ranging from 0.90 to 0.93 - a consistent structural relationship.

Return for Risk

MIDLX vs. COIIX — Risk / Return Rank

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

MIDLX

MIDLX Risk / Return Rank: 11
MIDLX Sharpe Ratio Rank: 12
MIDLX Sortino Ratio Rank: 12
MIDLX Omega Ratio Rank: 13
MIDLX Calmar Ratio Rank: 9
MIDLX Martin Ratio Rank: 11

COIIX

COIIX Risk / Return Rank: 6
COIIX Sharpe Ratio Rank: 6
COIIX Sortino Ratio Rank: 6
COIIX Omega Ratio Rank: 6
COIIX Calmar Ratio Rank: 6
COIIX Martin Ratio Rank: 7

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.

MIDLX vs. COIIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for MFS International New Discovery Fund Class R6 (MIDLX) and Calvert International Opportunities Fund (COIIX). 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.

	MIDLX	COIIX	Difference
Sharpe ratio: Return per unit of total volatility	0.94	0.52	+0.42
Sortino ratio: Return per unit of downside risk	1.41	0.84	+0.57
Omega ratio: Gain probability vs. loss probability	1.18	1.10	+0.07
Calmar ratio: Return relative to maximum drawdown	0.92	0.56	+0.36
Martin ratio: Return relative to average drawdown	3.17	1.98	+1.18
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

MIDLX vs. COIIX - Sharpe Ratio Comparison

The current MIDLX Sharpe Ratio is 0.94, which is higher than the COIIX Sharpe Ratio of 0.52. The chart below compares the historical Sharpe Ratios of MIDLX and COIIX, 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

	MIDLX	COIIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.94	0.52	+0.42
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.28	0.03	+0.25
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.49	0.38	+0.11
Sharpe Ratio (All Time) Calculated using the full available price history	0.59	0.23	+0.36

Drawdowns

MIDLX vs. COIIX - Drawdown Comparison

The maximum MIDLX drawdown since its inception was -34.70%, smaller than the maximum COIIX drawdown of -57.27%. Use the drawdown chart below to compare losses from any high point for MIDLX and COIIX.

Drawdown Indicators

	MIDLX	COIIX	Difference
Max Drawdown Largest peak-to-trough decline	-34.70%	-57.27%	+22.57%
Max Drawdown (1Y) Largest decline over 1 year	-11.75%	-12.74%	+0.99%
Max Drawdown (3Y) Largest decline over 3 years	-13.15%	-17.12%	+3.97%
Max Drawdown (5Y) Largest decline over 5 years	-33.58%	-40.36%	+6.78%
Max Drawdown (10Y) Largest decline over 10 years	-34.70%	-40.36%	+5.66%
Current Drawdown Current decline from peak	-1.64%	-4.78%	+3.14%
Average Drawdown Average peak-to-trough decline	-6.92%	-14.98%	+8.06%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.41%	3.62%	-0.21%

Volatility

MIDLX vs. COIIX - Volatility Comparison

MFS International New Discovery Fund Class R6 (MIDLX) and Calvert International Opportunities Fund (COIIX) have volatilities of 3.48% and 3.56%, 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

	MIDLX	COIIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.48%	3.56%	-0.08%
Volatility (6M) Calculated over the trailing 6-month period	9.46%	11.03%	-1.57%
Volatility (1Y) Calculated over the trailing 1-year period	11.52%	13.76%	-2.24%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	13.21%	16.97%	-3.76%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	14.01%	17.00%	-2.99%

MIDLX vs. COIIX - Expense Ratio Comparison

MIDLX has a 0.91% expense ratio, which is lower than COIIX's 1.06% expense ratio.

Dividends

MIDLX vs. COIIX - Dividend Comparison

MIDLX's dividend yield for the trailing twelve months is around 3.15%, less than COIIX's 3.28% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
COIIX Calvert International Opportunities Fund	3.28%	3.49%	3.24%	1.77%	0.61%	7.67%	0.78%	1.32%	9.82%	7.19%	1.52%	4.53%
MIDLX MFS International New Discovery Fund Class R6	3.15%	3.37%	10.08%	4.21%	5.85%	5.19%	4.03%	4.36%	6.82%	1.63%	1.09%	1.25%

Frequently Asked Questions

Can I hold both MIDLX and COIIX in my portfolio?

With a correlation of 0.91, MIDLX and COIIX 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, MIDLX or COIIX?

COIIX has higher volatility (3.56%) compared to MIDLX (3.48%). In terms of maximum drawdown, MIDLX dropped -34.70% vs COIIX's -57.27%.

Which has better risk-adjusted returns?

MIDLX currently has the higher Sharpe Ratio (0.94 vs 0.52), 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.