MSTDX vs. MIEYX

Last updated Jun 26, 2026

MSTDX (MassMutual Short Duration Bond Fund) and MIEYX (MM S&P 500 Index Fund) are both mutual funds - MSTDX is a Short-Term Bond fund managed by MassMutual, while MIEYX is a S&P 500 fund tracking the S&P 500 Index. Over the past 10 years, MSTDX returned 2.03%/yr vs 14.56%/yr for MIEYX. At a correlation of -0.08, they often move in opposite directions. MSTDX charges 0.51%/yr vs 0.46%/yr for MIEYX.

Performance

MSTDX vs. MIEYX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in MassMutual Short Duration Bond Fund (MSTDX) and MM S&P 500 Index Fund (MIEYX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, MSTDX achieves a 0.73% return, which is significantly lower than MIEYX's 7.87% return. Over the past 10 years, MSTDX has underperformed MIEYX with an annualized return of 2.03%, while MIEYX has yielded a comparatively higher 14.56% annualized return.

MSTDX

• 1D: 0.11%
• 1M: 0.22%
• YTD: 0.73%
• 6M: 1.24%
• 1Y: 3.95%
• 3Y*: 5.66%
• 5Y*: 1.30%
• 10Y*: 2.03%

MIEYX

• 1D: -0.07%
• 1M: -2.08%
• YTD: 7.87%
• 6M: 6.58%
• 1Y: 21.64%
• 3Y*: 20.22%
• 5Y*: 12.46%
• 10Y*: 14.56%

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

MSTDX vs. MIEYX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
MSTDX MassMutual Short Duration Bond Fund	0.73%	6.18%	6.38%	5.88%	-11.19%	1.79%	2.29%	4.49%	1.68%	2.61%
MIEYX MM S&P 500 Index Fund	7.87%	17.27%	24.36%	25.76%	-18.63%	28.02%	17.87%	30.98%	-5.26%	18.90%

Correlation

The correlation between MSTDX and MIEYX is 0.25, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.25
Correlation (3Y) Calculated over the trailing 3-year period	0.17
Correlation (5Y) Calculated over the trailing 5-year period	0.18
Correlation (10Y) Calculated over the trailing 10-year period	0.12
Correlation (All Time) Calculated using the full available price history since Feb 27, 1998	-0.08

The correlation between MSTDX and MIEYX shifts across timeframes, from -0.08 (all time) to 0.25 (1 year), reflecting how their relationship changes across market environments.

Return for Risk

MSTDX vs. MIEYX — Risk / Return Rank

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

MSTDX

MSTDX Risk / Return Rank: 89
MSTDX Sharpe Ratio Rank: 80
MSTDX Sortino Ratio Rank: 92
MSTDX Omega Ratio Rank: 90
MSTDX Calmar Ratio Rank: 89
MSTDX Martin Ratio Rank: 92

MIEYX

MIEYX Risk / Return Rank: 53
MIEYX Sharpe Ratio Rank: 50
MIEYX Sortino Ratio Rank: 46
MIEYX Omega Ratio Rank: 49
MIEYX Calmar Ratio Rank: 54
MIEYX Martin Ratio Rank: 66

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.

MSTDX vs. MIEYX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for MassMutual Short Duration Bond Fund (MSTDX) and MM S&P 500 Index Fund (MIEYX). 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.

	MSTDX	MIEYX	Difference
Sharpe ratio: Return per unit of total volatility	2.22	1.74	+0.49
Sortino ratio: Return per unit of downside risk	4.12	2.38	+1.74
Omega ratio: Gain probability vs. loss probability	1.58	1.32	+0.26
Calmar ratio: Return relative to maximum drawdown	3.84	2.44	+1.40
Martin ratio: Return relative to average drawdown	15.84	10.85	+5.00

MSTDX vs. MIEYX - Sharpe Ratio Comparison

The current MSTDX Sharpe Ratio is 2.22, which is comparable to the MIEYX Sharpe Ratio of 1.74. The chart below compares the historical Sharpe Ratios of MSTDX and MIEYX, 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

MSTDX vs. MIEYX - Drawdown Comparison

The maximum MSTDX drawdown since its inception was -13.31%, smaller than the maximum MIEYX drawdown of -55.63%. Use the drawdown chart below to compare losses from any high point for MSTDX and MIEYX.

Drawdown Indicators

	MSTDX	MIEYX	Difference
Max Drawdown Largest peak-to-trough decline	-13.31%	-55.63%	+42.32%
Max Drawdown (1Y) Largest decline over 1 year	-1.06%	-8.92%	+7.86%
Max Drawdown (3Y) Largest decline over 3 years	-1.06%	-36.63%	+35.57%
Max Drawdown (5Y) Largest decline over 5 years	-13.31%	-36.63%	+23.32%
Max Drawdown (10Y) Largest decline over 10 years	-13.31%	-36.63%	+23.32%
Current Drawdown Current decline from peak	-0.21%	-5.56%	+5.35%
Average Drawdown Average peak-to-trough decline	-1.42%	-12.55%	+11.13%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.26%	2.00%	-1.74%

Volatility

MSTDX vs. MIEYX - Volatility Comparison

The current volatility for MassMutual Short Duration Bond Fund (MSTDX) is 0.63%, while MM S&P 500 Index Fund (MIEYX) has a volatility of 4.89%. This indicates that MSTDX experiences smaller price fluctuations and is considered to be less risky than MIEYX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	MSTDX	MIEYX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.63%	4.89%	-4.26%
Volatility (6M) Calculated over the trailing 6-month period	1.41%	9.90%	-8.49%
Volatility (1Y) Calculated over the trailing 1-year period	1.83%	12.56%	-10.73%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	2.34%	25.58%	-23.24%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	2.06%	22.58%	-20.52%

MSTDX vs. MIEYX - Expense Ratio Comparison

MSTDX has a 0.51% expense ratio, which is higher than MIEYX's 0.46% expense ratio.

Dividends

MSTDX vs. MIEYX - Dividend Comparison

MSTDX's dividend yield for the trailing twelve months is around 4.44%, less than MIEYX's 16.35% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
MIEYX MM S&P 500 Index Fund	16.35%	17.63%	32.89%	7.13%	33.24%	13.29%	16.29%	6.38%	19.14%	21.81%	4.19%	2.29%
MSTDX MassMutual Short Duration Bond Fund	4.44%	4.36%	2.63%	2.48%	1.46%	1.90%	4.44%	3.35%	3.82%	2.51%	2.36%	2.57%

Frequently Asked Questions

Can I hold both MSTDX and MIEYX in my portfolio?

MSTDX and MIEYX have a correlation of 0.25, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, MSTDX or MIEYX?

MIEYX has higher volatility (4.89%) compared to MSTDX (0.63%). In terms of maximum drawdown, MSTDX dropped -13.31% vs MIEYX's -55.63%.

Which has better risk-adjusted returns?

MSTDX currently has the higher Sharpe Ratio (2.22 vs 1.74), 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.