MRBIX vs. BMSIX
MRBIX (MFS Total Return Bond Fund) and BMSIX (BlackRock Income Fund) are both mutual funds - MRBIX is a Intermediate Core-Plus Bond fund managed by MFS, while BMSIX is a Multisector Bonds fund managed by BlackRock. Over the past 10 years, MRBIX returned 1.96%/yr vs 3.85%/yr for BMSIX. A 0.60 correlation means they provide meaningful diversification when combined. MRBIX charges 0.45%/yr vs 0.62%/yr for BMSIX.
Performance
MRBIX vs. BMSIX - Performance Comparison
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Returns By Period
In the year-to-date period, MRBIX achieves a 0.52% return, which is significantly higher than BMSIX's 0.35% return. Over the past 10 years, MRBIX has underperformed BMSIX with an annualized return of 1.96%, while BMSIX has yielded a comparatively higher 3.85% annualized return.
MRBIX
- 1D
- 0.21%
- 1M
- 0.87%
- YTD
- 0.52%
- 6M
- 0.89%
- 1Y
- 5.00%
- 3Y*
- 4.35%
- 5Y*
- 0.03%
- 10Y*
- 1.96%
BMSIX
- 1D
- 0.11%
- 1M
- 0.65%
- YTD
- 0.35%
- 6M
- 1.05%
- 1Y
- 5.63%
- 3Y*
- 6.79%
- 5Y*
- 1.79%
- 10Y*
- 3.85%
MRBIX vs. BMSIX - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
MRBIX MFS Total Return Bond Fund | 0.52% | 7.35% | 1.77% | 6.45% | -14.52% | -0.84% | 8.83% | 9.96% | -1.03% | 4.15% |
BMSIX BlackRock Income Fund | 0.35% | 8.38% | 5.96% | 7.84% | -10.08% | -0.29% | 6.94% | 12.03% | -1.03% | 6.62% |
Correlation
The correlation between MRBIX and BMSIX is 0.82, 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 | 0.82 |
Correlation (3Y) Calculated over the trailing 3-year period | 0.88 |
Correlation (5Y) Calculated over the trailing 5-year period | 0.80 |
Correlation (10Y) Calculated over the trailing 10-year period | 0.67 |
Correlation (All Time) Calculated using the full available price history since Mar 1, 2010 | 0.60 |
Over the past year, MRBIX and BMSIX have become more correlated (0.82) than their long-term average of 0.60, meaning their price movements have been converging.
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Return for Risk
MRBIX vs. BMSIX — Risk / Return Rank
MRBIX
BMSIX
MRBIX vs. BMSIX - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for MFS Total Return Bond Fund (MRBIX) and BlackRock Income Fund (BMSIX). 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.
| MRBIX | BMSIX | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | -0.63 | ||
| Sortino ratioReturn per unit of downside risk | -1.20 | ||
| Omega ratioGain probability vs. loss probability | 1.24 | 1.41 | -0.17 |
| Calmar ratioReturn relative to maximum drawdown | 1.81 | 2.25 | -0.43 |
| Martin ratioReturn relative to average drawdown | 5.03 | 9.47 | -4.44 |
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Drawdowns
MRBIX vs. BMSIX - Drawdown Comparison
The maximum MRBIX drawdown since its inception was -19.25%, roughly equal to the maximum BMSIX drawdown of -18.60%. Use the drawdown chart below to compare losses from any high point for MRBIX and BMSIX.
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Drawdown Indicators
| MRBIX | BMSIX | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -19.25% | -18.60% | -0.65% |
Max Drawdown (1Y)Largest decline over 1 year | -2.77% | -2.51% | -0.26% |
Max Drawdown (3Y)Largest decline over 3 years | -6.29% | -2.58% | -3.71% |
Max Drawdown (5Y)Largest decline over 5 years | -19.25% | -16.52% | -2.73% |
Max Drawdown (10Y)Largest decline over 10 years | -19.25% | -18.60% | -0.65% |
Current DrawdownCurrent decline from peak | -1.29% | -0.37% | -0.92% |
Average DrawdownAverage peak-to-trough decline | -2.47% | -2.03% | -0.44% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 1.00% | 0.60% | +0.40% |
Volatility
MRBIX vs. BMSIX - Volatility Comparison
MFS Total Return Bond Fund (MRBIX) has a higher volatility of 1.21% compared to BlackRock Income Fund (BMSIX) at 0.99%. This indicates that MRBIX's price experiences larger fluctuations and is considered to be riskier than BMSIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.
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Volatility by Period
| MRBIX | BMSIX | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 1.21% | 0.99% | +0.22% |
Volatility (6M)Calculated over the trailing 6-month period | 2.79% | 2.36% | +0.43% |
Volatility (1Y)Calculated over the trailing 1-year period | 3.78% | 2.89% | +0.89% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 5.73% | 3.78% | +1.95% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 4.92% | 4.15% | +0.77% |
MRBIX vs. BMSIX - Expense Ratio Comparison
MRBIX has a 0.45% expense ratio, which is lower than BMSIX's 0.62% expense ratio.
Dividends
MRBIX vs. BMSIX - Dividend Comparison
MRBIX's dividend yield for the trailing twelve months is around 4.17%, less than BMSIX's 5.64% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
BMSIX BlackRock Income Fund | 5.64% | 5.66% | 5.99% | 4.38% | 3.71% | 5.31% | 4.19% | 4.90% | 5.13% | 4.03% | 4.49% | 4.35% |
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
MRBIX and BMSIX have a correlation of 0.82, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.
MRBIX has higher volatility (1.21%) compared to BMSIX (0.99%). In terms of maximum drawdown, MRBIX dropped -19.25% vs BMSIX's -18.60%.
BMSIX currently has the higher Sharpe Ratio (1.96 vs 1.33), 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.
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