BBSOX vs. MUIIX

Last updated Jun 4, 2026

BBSOX (BlackRock Short Obligations Fund) and MUIIX (Morgan Stanley Institutional Fund Trust Ultra-Short Income Portfolio) are both Ultrashort Bond funds. Over the past 5 years, BBSOX returned 3.27%/yr vs 3.25%/yr for MUIIX. At a 0.31 correlation, their price movements are largely independent. BBSOX charges 0.30%/yr vs 0.35%/yr for MUIIX.

Performance

BBSOX vs. MUIIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in BlackRock Short Obligations Fund (BBSOX) and Morgan Stanley Institutional Fund Trust Ultra-Short Income Portfolio (MUIIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, BBSOX achieves a 1.49% return, which is significantly lower than MUIIX's 1.57% return.

BBSOX

• 1D: 0.00%
• 1M: 0.34%
• YTD: 1.49%
• 6M: 1.85%
• 1Y: 4.24%
• 3Y*: 4.77%
• 5Y*: 3.27%
• 10Y*: 2.48%

MUIIX

• 1D: 0.00%
• 1M: 0.32%
• YTD: 1.57%
• 6M: 1.91%
• 1Y: 4.22%
• 3Y*: 4.41%
• 5Y*: 3.25%
• 10Y*: —

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

BBSOX vs. MUIIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020
BBSOX BlackRock Short Obligations Fund	1.49%	4.74%	5.36%	4.36%	0.60%	-0.10%	1.66%
MUIIX Morgan Stanley Institutional Fund Trust Ultra-Short Income Portfolio	1.57%	4.47%	4.94%	4.17%	1.10%	0.10%	0.49%

Correlation

The correlation between BBSOX and MUIIX is 0.60, 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	0.60
Correlation (3Y) Calculated over the trailing 3-year period	0.35
Correlation (5Y) Calculated over the trailing 5-year period	0.30
Correlation (All Time) Calculated using the full available price history since Apr 8, 2020	0.31

Over the past year, BBSOX and MUIIX have become more correlated (0.60) than their long-term average of 0.31, meaning their price movements have been converging.

Return for Risk

BBSOX vs. MUIIX — Risk / Return Rank

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

BBSOX

BBSOX Risk / Return Rank: 98
BBSOX Sharpe Ratio Rank: 93
BBSOX Sortino Ratio Rank: 100
BBSOX Omega Ratio Rank: 99
BBSOX Calmar Ratio Rank: 100
BBSOX Martin Ratio Rank: 99

MUIIX

MUIIX Risk / Return Rank: 99
MUIIX Sharpe Ratio Rank: 97
MUIIX Sortino Ratio Rank: 100
MUIIX Omega Ratio Rank: 100
MUIIX Calmar Ratio Rank: 100
MUIIX Martin Ratio Rank: 100

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.

BBSOX vs. MUIIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for BlackRock Short Obligations Fund (BBSOX) and Morgan Stanley Institutional Fund Trust Ultra-Short Income Portfolio (MUIIX). 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.

	BBSOX	MUIIX	Difference
Sharpe ratio Return per unit of total volatility	3.20	3.61	-0.42
Sortino ratio Return per unit of downside risk	11.68	23.95	-12.28
Omega ratio Gain probability vs. loss probability	4.23	14.80	-10.57
Calmar ratio Return relative to maximum drawdown	21.50	42.37	-20.88
Martin ratio Return relative to average drawdown	70.26	126.87	-56.60
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

BBSOX vs. MUIIX - Sharpe Ratio Comparison

The current BBSOX Sharpe Ratio is 3.20, which is comparable to the MUIIX Sharpe Ratio of 3.61. The chart below compares the historical Sharpe Ratios of BBSOX and MUIIX, 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

	BBSOX	MUIIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	3.20	3.61	-0.42
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	2.63	2.05	+0.57
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	2.42	—	—
Sharpe Ratio (All Time) Calculated using the full available price history	2.24	1.90	+0.34

Drawdowns

BBSOX vs. MUIIX - Drawdown Comparison

The maximum BBSOX drawdown since its inception was -1.59%, which is greater than MUIIX's maximum drawdown of -1.20%. Use the drawdown chart below to compare losses from any high point for BBSOX and MUIIX.

Drawdown Indicators

	BBSOX	MUIIX	Difference
Max Drawdown Largest peak-to-trough decline	-1.59%	-1.20%	-0.39%
Max Drawdown (1Y) Largest decline over 1 year	-0.20%	-0.10%	-0.10%
Max Drawdown (3Y) Largest decline over 3 years	-0.30%	-1.20%	+0.90%
Max Drawdown (5Y) Largest decline over 5 years	-1.00%	-1.20%	+0.20%
Max Drawdown (10Y) Largest decline over 10 years	-1.59%	—	—
Current Drawdown Current decline from peak	0.00%	0.00%	0.00%
Average Drawdown Average peak-to-trough decline	-0.08%	-0.06%	-0.02%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.06%	0.03%	+0.03%

Volatility

BBSOX vs. MUIIX - Volatility Comparison

BlackRock Short Obligations Fund (BBSOX) has a higher volatility of 0.40% compared to Morgan Stanley Institutional Fund Trust Ultra-Short Income Portfolio (MUIIX) at 0.35%. This indicates that BBSOX's price experiences larger fluctuations and is considered to be riskier than MUIIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	BBSOX	MUIIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.40%	0.35%	+0.05%
Volatility (6M) Calculated over the trailing 6-month period	0.88%	0.78%	+0.10%
Volatility (1Y) Calculated over the trailing 1-year period	1.33%	1.17%	+0.16%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	1.25%	1.59%	-0.34%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	1.03%	1.44%	-0.41%

BBSOX vs. MUIIX - Expense Ratio Comparison

BBSOX has a 0.30% expense ratio, which is lower than MUIIX's 0.35% expense ratio.

Dividends

BBSOX vs. MUIIX - Dividend Comparison

BBSOX's dividend yield for the trailing twelve months is around 4.25%, more than MUIIX's 4.03% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BBSOX BlackRock Short Obligations Fund	4.25%	4.43%	5.01%	3.35%	1.29%	0.30%	1.13%	2.56%	2.24%	1.17%	1.03%	0.62%
MUIIX Morgan Stanley Institutional Fund Trust Ultra-Short Income Portfolio	4.03%	4.36%	4.81%	3.88%	1.20%	0.10%	0.39%	0.00%	0.00%	0.00%	0.00%	0.00%

Frequently Asked Questions

Can I hold both BBSOX and MUIIX in my portfolio?

BBSOX and MUIIX have a correlation of 0.60, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, BBSOX or MUIIX?

BBSOX has higher volatility (0.40%) compared to MUIIX (0.35%). In terms of maximum drawdown, BBSOX dropped -1.59% vs MUIIX's -1.20%.

Which has better risk-adjusted returns?

MUIIX currently has the higher Sharpe Ratio (3.61 vs 3.20), 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.