MRBIX vs. EINFX

Last updated Jun 5, 2026

MRBIX (MFS Total Return Bond Fund) and EINFX (Elfun Income Fund) are both Intermediate Core-Plus Bond funds. Over the past 10 years, MRBIX returned 1.95%/yr vs 1.34%/yr for EINFX. Their correlation of 0.90 suggests significant overlap in exposure. MRBIX charges 0.45%/yr vs 0.29%/yr for EINFX.

Performance

MRBIX vs. EINFX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in MFS Total Return Bond Fund (MRBIX) and Elfun Income Fund (EINFX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, MRBIX achieves a 0.31% return, which is significantly higher than EINFX's -0.17% return. Over the past 10 years, MRBIX has outperformed EINFX with an annualized return of 1.95%, while EINFX has yielded a comparatively lower 1.34% annualized return.

MRBIX

• 1D: -0.21%
• 1M: 0.13%
• YTD: 0.31%
• 6M: 0.47%
• 1Y: 4.78%
• 3Y*: 4.28%
• 5Y*: 0.11%
• 10Y*: 1.95%

EINFX

• 1D: -0.21%
• 1M: 0.05%
• YTD: -0.17%
• 6M: -0.05%
• 1Y: 4.22%
• 3Y*: 2.91%
• 5Y*: -0.73%
• 10Y*: 1.34%

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

MRBIX vs. EINFX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
MRBIX MFS Total Return Bond Fund	0.31%	7.35%	1.77%	6.45%	-14.52%	-0.84%	8.83%	9.96%	-1.03%	4.15%
EINFX Elfun Income Fund	-0.17%	7.35%	-0.73%	4.75%	-13.82%	-1.57%	7.81%	9.51%	-0.86%	3.91%

Correlation

The correlation between MRBIX and EINFX is 0.96 - 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	0.96
Correlation (3Y) Calculated over the trailing 3-year period	0.97
Correlation (5Y) Calculated over the trailing 5-year period	0.97
Correlation (10Y) Calculated over the trailing 10-year period	0.95
Correlation (All Time) Calculated using the full available price history since Jan 4, 1999	0.90

The correlation between MRBIX and EINFX has been stable across timeframes, ranging from 0.90 to 0.97 - a consistent structural relationship.

Return for Risk

MRBIX vs. EINFX — Risk / Return Rank

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

MRBIX

MRBIX Risk / Return Rank: 26
MRBIX Sharpe Ratio Rank: 25
MRBIX Sortino Ratio Rank: 28
MRBIX Omega Ratio Rank: 24
MRBIX Calmar Ratio Rank: 29
MRBIX Martin Ratio Rank: 24

EINFX

EINFX Risk / Return Rank: 16
EINFX Sharpe Ratio Rank: 17
EINFX Sortino Ratio Rank: 17
EINFX Omega Ratio Rank: 16
EINFX Calmar Ratio Rank: 17
EINFX Martin Ratio Rank: 16

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.

MRBIX vs. EINFX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for MFS Total Return Bond Fund (MRBIX) and Elfun Income Fund (EINFX). 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.

	MRBIX	EINFX	Difference
Sharpe ratio: Return per unit of total volatility	1.42	1.15	+0.27
Sortino ratio: Return per unit of downside risk	2.15	1.74	+0.41
Omega ratio: Gain probability vs. loss probability	1.25	1.20	+0.05
Calmar ratio: Return relative to maximum drawdown	1.98	1.44	+0.54
Martin ratio: Return relative to average drawdown	5.76	4.32	+1.44
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

MRBIX vs. EINFX - Sharpe Ratio Comparison

The current MRBIX Sharpe Ratio is 1.42, which is comparable to the EINFX Sharpe Ratio of 1.15. The chart below compares the historical Sharpe Ratios of MRBIX and EINFX, 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

	MRBIX	EINFX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.42	1.15	+0.27
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.02	-0.11	+0.13
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.40	0.26	+0.14
Sharpe Ratio (All Time) Calculated using the full available price history	0.97	0.79	+0.19

Drawdowns

MRBIX vs. EINFX - Drawdown Comparison

The maximum MRBIX drawdown since its inception was -19.25%, roughly equal to the maximum EINFX drawdown of -19.78%. Use the drawdown chart below to compare losses from any high point for MRBIX and EINFX.

Drawdown Indicators

	MRBIX	EINFX	Difference
Max Drawdown Largest peak-to-trough decline	-19.25%	-19.78%	+0.53%
Max Drawdown (1Y) Largest decline over 1 year	-2.77%	-3.40%	+0.63%
Max Drawdown (3Y) Largest decline over 3 years	-6.29%	-8.10%	+1.81%
Max Drawdown (5Y) Largest decline over 5 years	-19.25%	-19.78%	+0.53%
Max Drawdown (10Y) Largest decline over 10 years	-19.25%	-19.78%	+0.53%
Current Drawdown Current decline from peak	-1.50%	-5.45%	+3.95%
Average Drawdown Average peak-to-trough decline	-2.47%	-3.57%	+1.10%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.95%	1.13%	-0.18%

Volatility

MRBIX vs. EINFX - Volatility Comparison

The current volatility for MFS Total Return Bond Fund (MRBIX) is 1.30%, while Elfun Income Fund (EINFX) has a volatility of 1.46%. This indicates that MRBIX experiences smaller price fluctuations and is considered to be less risky than EINFX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	MRBIX	EINFX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.30%	1.46%	-0.16%
Volatility (6M) Calculated over the trailing 6-month period	2.70%	2.93%	-0.23%
Volatility (1Y) Calculated over the trailing 1-year period	3.85%	4.24%	-0.39%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	5.73%	6.50%	-0.77%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	4.92%	5.23%	-0.31%

MRBIX vs. EINFX - Expense Ratio Comparison

MRBIX has a 0.45% expense ratio, which is higher than EINFX's 0.29% expense ratio.

Dividends

MRBIX vs. EINFX - Dividend Comparison

MRBIX's dividend yield for the trailing twelve months is around 4.17%, more than EINFX's 3.86% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
EINFX Elfun Income Fund	3.86%	3.84%	3.04%	2.76%	4.09%	3.31%	3.15%	2.78%	2.88%	2.42%	3.34%	2.87%
MRBIX MFS Total Return Bond Fund	4.17%	4.21%	3.69%	3.42%	2.39%	3.42%	3.00%	3.06%	2.87%	2.65%	3.02%	3.76%

Frequently Asked Questions

Can I hold both MRBIX and EINFX in my portfolio?

With a correlation of 0.96, MRBIX and EINFX 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, MRBIX or EINFX?

EINFX has higher volatility (1.46%) compared to MRBIX (1.30%). In terms of maximum drawdown, MRBIX dropped -19.25% vs EINFX's -19.78%.

Which has better risk-adjusted returns?

MRBIX currently has the higher Sharpe Ratio (1.42 vs 1.15), 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.