MOSAX vs. MEFAX

Last updated Jun 3, 2026

MOSAX (MassMutual Overseas Fund) and MEFAX (MassMutual Mid Cap Growth Fund) are both mutual funds - MOSAX is a Foreign Large Cap Equities fund managed by MassMutual, while MEFAX is a Mid Cap Growth Equities fund managed by MassMutual. Over the past 10 years, MOSAX returned 8.27%/yr vs 10.32%/yr for MEFAX. A 0.71 correlation means they provide meaningful diversification when combined. MOSAX charges 1.34%/yr vs 1.20%/yr for MEFAX.

Performance

MOSAX vs. MEFAX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in MassMutual Overseas Fund (MOSAX) and MassMutual Mid Cap Growth Fund (MEFAX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, MOSAX achieves a 2.34% return, which is significantly lower than MEFAX's 5.32% return. Over the past 10 years, MOSAX has underperformed MEFAX with an annualized return of 8.27%, while MEFAX has yielded a comparatively higher 10.32% annualized return.

MOSAX

• 1D: -0.23%
• 1M: 2.58%
• YTD: 2.34%
• 6M: 5.32%
• 1Y: 9.90%
• 3Y*: 10.44%
• 5Y*: 5.09%
• 10Y*: 8.27%

MEFAX

• 1D: 0.19%
• 1M: 2.74%
• YTD: 5.32%
• 6M: 5.34%
• 1Y: 12.16%
• 3Y*: 9.99%
• 5Y*: 3.13%
• 10Y*: 10.32%

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

MOSAX vs. MEFAX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
MOSAX MassMutual Overseas Fund	2.34%	25.48%	0.12%	18.26%	-15.35%	12.61%	8.51%	28.26%	-16.78%	26.44%
MEFAX MassMutual Mid Cap Growth Fund	5.32%	3.19%	10.80%	19.11%	-24.58%	13.75%	25.52%	40.75%	-3.88%	24.12%

Correlation

The correlation between MOSAX and MEFAX is 0.70, 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	0.70
Correlation (3Y) Calculated over the trailing 3-year period	0.69
Correlation (5Y) Calculated over the trailing 5-year period	0.72
Correlation (10Y) Calculated over the trailing 10-year period	0.72
Correlation (All Time) Calculated using the full available price history since May 3, 2001	0.71

The correlation between MOSAX and MEFAX has been stable across timeframes, ranging from 0.69 to 0.72 - a consistent structural relationship.

Return for Risk

MOSAX vs. MEFAX — Risk / Return Rank

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

MOSAX

MOSAX Risk / Return Rank: 9
MOSAX Sharpe Ratio Rank: 9
MOSAX Sortino Ratio Rank: 9
MOSAX Omega Ratio Rank: 9
MOSAX Calmar Ratio Rank: 9
MOSAX Martin Ratio Rank: 10

MEFAX

MEFAX Risk / Return Rank: 12
MEFAX Sharpe Ratio Rank: 11
MEFAX Sortino Ratio Rank: 11
MEFAX Omega Ratio Rank: 10
MEFAX Calmar Ratio Rank: 12
MEFAX Martin Ratio Rank: 15

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.

MOSAX vs. MEFAX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for MassMutual Overseas Fund (MOSAX) and MassMutual Mid Cap Growth Fund (MEFAX). 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.

	MOSAX	MEFAX	Difference
Sharpe ratio Return per unit of total volatility	0.76	0.86	-0.10
Sortino ratio Return per unit of downside risk	1.16	1.33	-0.17
Omega ratio Gain probability vs. loss probability	1.14	1.15	-0.01
Calmar ratio Return relative to maximum drawdown	0.92	1.22	-0.29
Martin ratio Return relative to average drawdown	3.17	4.45	-1.28
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

MOSAX vs. MEFAX - Sharpe Ratio Comparison

The current MOSAX Sharpe Ratio is 0.76, which is comparable to the MEFAX Sharpe Ratio of 0.86. The chart below compares the historical Sharpe Ratios of MOSAX and MEFAX, 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

	MOSAX	MEFAX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.76	0.86	-0.10
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.29	0.11	+0.18
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.46	0.43	+0.02
Sharpe Ratio (All Time) Calculated using the full available price history	0.28	0.39	-0.11

Drawdowns

MOSAX vs. MEFAX - Drawdown Comparison

The maximum MOSAX drawdown since its inception was -58.43%, roughly equal to the maximum MEFAX drawdown of -56.04%. Use the drawdown chart below to compare losses from any high point for MOSAX and MEFAX.

Drawdown Indicators

	MOSAX	MEFAX	Difference
Max Drawdown Largest peak-to-trough decline	-58.43%	-56.04%	-2.39%
Max Drawdown (1Y) Largest decline over 1 year	-11.74%	-10.45%	-1.29%
Max Drawdown (3Y) Largest decline over 3 years	-14.43%	-34.46%	+20.03%
Max Drawdown (5Y) Largest decline over 5 years	-33.69%	-45.14%	+11.45%
Max Drawdown (10Y) Largest decline over 10 years	-36.75%	-45.14%	+8.39%
Current Drawdown Current decline from peak	-2.13%	-14.19%	+12.06%
Average Drawdown Average peak-to-trough decline	-11.62%	-11.43%	-0.19%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.42%	2.85%	+0.57%

Volatility

MOSAX vs. MEFAX - Volatility Comparison

MassMutual Overseas Fund (MOSAX) has a higher volatility of 4.12% compared to MassMutual Mid Cap Growth Fund (MEFAX) at 3.87%. This indicates that MOSAX's price experiences larger fluctuations and is considered to be riskier than MEFAX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	MOSAX	MEFAX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.12%	3.87%	+0.25%
Volatility (6M) Calculated over the trailing 6-month period	10.86%	11.27%	-0.41%
Volatility (1Y) Calculated over the trailing 1-year period	13.97%	14.66%	-0.69%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	17.67%	27.46%	-9.79%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	18.22%	23.94%	-5.72%

MOSAX vs. MEFAX - Expense Ratio Comparison

MOSAX has a 1.34% expense ratio, which is higher than MEFAX's 1.20% expense ratio.

Dividends

MOSAX vs. MEFAX - Dividend Comparison

MOSAX's dividend yield for the trailing twelve months is around 17.79%, less than MEFAX's 32.43% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
MEFAX MassMutual Mid Cap Growth Fund	32.43%	34.16%	21.40%	7.62%	20.71%	29.49%	6.92%	12.81%	12.06%	7.66%	5.32%	10.27%
MOSAX MassMutual Overseas Fund	17.79%	18.21%	6.02%	2.24%	9.26%	9.64%	1.78%	5.10%	12.16%	1.42%	1.71%	3.12%

Frequently Asked Questions

Can I hold both MOSAX and MEFAX in my portfolio?

MOSAX and MEFAX have a correlation of 0.70, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, MOSAX or MEFAX?

MOSAX has higher volatility (4.12%) compared to MEFAX (3.87%). In terms of maximum drawdown, MOSAX dropped -58.43% vs MEFAX's -56.04%.

Which has better risk-adjusted returns?

MEFAX currently has the higher Sharpe Ratio (0.86 vs 0.76), 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.