MUOIX vs. VIIIX

Last updated Jun 4, 2026

MUOIX (Morgan Stanley Institutional Fund, Inc. US Core Portfolio) and VIIIX (Vanguard Institutional Index Fund Institutional Plus Shares) are both Large Cap Blend Equities funds. Over the past 5 years, MUOIX returned 11.65%/yr vs 14.42%/yr for VIIIX. With a 0.95 correlation, they move nearly in lockstep. MUOIX charges 0.80%/yr vs 0.02%/yr for VIIIX.

Performance

MUOIX vs. VIIIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Morgan Stanley Institutional Fund, Inc. US Core Portfolio (MUOIX) and Vanguard Institutional Index Fund Institutional Plus Shares (VIIIX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, MUOIX achieves a 3.97% return, which is significantly lower than VIIIX's 11.70% return.

MUOIX

• 1D: -0.97%
• 1M: 2.93%
• YTD: 3.97%
• 6M: 4.00%
• 1Y: 17.19%
• 3Y*: 21.11%
• 5Y*: 11.65%
• 10Y*: —

VIIIX

• 1D: 0.13%
• 1M: 5.80%
• YTD: 11.70%
• 6M: 11.74%
• 1Y: 28.99%
• 3Y*: 23.17%
• 5Y*: 14.42%
• 10Y*: 15.74%

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

MUOIX vs. VIIIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
MUOIX Morgan Stanley Institutional Fund, Inc. US Core Portfolio	3.97%	16.48%	28.61%	18.07%	-20.21%	35.99%	24.20%	36.01%	-11.00%	17.98%
VIIIX Vanguard Institutional Index Fund Institutional Plus Shares	11.70%	17.87%	26.29%	25.79%	-18.14%	28.69%	18.41%	31.48%	-4.41%	20.79%

Correlation

The correlation between MUOIX and VIIIX is 0.92, 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	0.92
Correlation (3Y) Calculated over the trailing 3-year period	0.94
Correlation (5Y) Calculated over the trailing 5-year period	0.95
Correlation (All Time) Calculated using the full available price history since Jan 4, 2017	0.95

The correlation between MUOIX and VIIIX has been stable across timeframes, ranging from 0.92 to 0.95 - a consistent structural relationship.

Return for Risk

MUOIX vs. VIIIX — Risk / Return Rank

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

MUOIX

MUOIX Risk / Return Rank: 20
MUOIX Sharpe Ratio Rank: 23
MUOIX Sortino Ratio Rank: 21
MUOIX Omega Ratio Rank: 23
MUOIX Calmar Ratio Rank: 14
MUOIX Martin Ratio Rank: 17

VIIIX

VIIIX Risk / Return Rank: 73
VIIIX Sharpe Ratio Rank: 76
VIIIX Sortino Ratio Rank: 67
VIIIX Omega Ratio Rank: 67
VIIIX Calmar Ratio Rank: 74
VIIIX Martin Ratio Rank: 83

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.

MUOIX vs. VIIIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Morgan Stanley Institutional Fund, Inc. US Core Portfolio (MUOIX) and Vanguard Institutional Index Fund Institutional Plus Shares (VIIIX). 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.

	MUOIX	VIIIX	Difference
Sharpe ratio: Return per unit of total volatility	1.37	2.52	-1.15
Sortino ratio: Return per unit of downside risk	1.94	3.42	-1.49
Omega ratio: Gain probability vs. loss probability	1.25	1.46	-0.21
Calmar ratio: Return relative to maximum drawdown	1.28	3.36	-2.08
Martin ratio: Return relative to average drawdown	4.71	15.69	-10.98
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

MUOIX vs. VIIIX - Sharpe Ratio Comparison

The current MUOIX Sharpe Ratio is 1.37, which is lower than the VIIIX Sharpe Ratio of 2.52. The chart below compares the historical Sharpe Ratios of MUOIX and VIIIX, 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

	MUOIX	VIIIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.37	2.52	-1.15
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.65	0.86	-0.21
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	—	0.87	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.72	0.50	+0.22

Drawdowns

MUOIX vs. VIIIX - Drawdown Comparison

The maximum MUOIX drawdown since its inception was -38.35%, smaller than the maximum VIIIX drawdown of -55.18%. Use the drawdown chart below to compare losses from any high point for MUOIX and VIIIX.

Drawdown Indicators

	MUOIX	VIIIX	Difference
Max Drawdown Largest peak-to-trough decline	-38.35%	-55.18%	+16.83%
Max Drawdown (1Y) Largest decline over 1 year	-13.75%	-8.90%	-4.85%
Max Drawdown (3Y) Largest decline over 3 years	-18.60%	-18.75%	+0.15%
Max Drawdown (5Y) Largest decline over 5 years	-24.92%	-24.50%	-0.42%
Max Drawdown (10Y) Largest decline over 10 years	—	-33.79%	—
Current Drawdown Current decline from peak	-1.02%	0.00%	-1.02%
Average Drawdown Average peak-to-trough decline	-6.22%	-10.02%	+3.80%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.72%	1.90%	+1.82%

Volatility

MUOIX vs. VIIIX - Volatility Comparison

Morgan Stanley Institutional Fund, Inc. US Core Portfolio (MUOIX) has a higher volatility of 3.21% compared to Vanguard Institutional Index Fund Institutional Plus Shares (VIIIX) at 2.83%. This indicates that MUOIX's price experiences larger fluctuations and is considered to be riskier than VIIIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	MUOIX	VIIIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.21%	2.83%	+0.38%
Volatility (6M) Calculated over the trailing 6-month period	9.94%	8.97%	+0.97%
Volatility (1Y) Calculated over the trailing 1-year period	12.83%	11.86%	+0.97%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	18.01%	16.89%	+1.12%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	20.14%	18.06%	+2.08%

MUOIX vs. VIIIX - Expense Ratio Comparison

MUOIX has a 0.80% expense ratio, which is higher than VIIIX's 0.02% expense ratio.

Dividends

MUOIX vs. VIIIX - Dividend Comparison

MUOIX has not paid dividends to shareholders, while VIIIX's dividend yield for the trailing twelve months is around 2.41%.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
MUOIX Morgan Stanley Institutional Fund, Inc. US Core Portfolio	0.00%	0.00%	0.08%	0.32%	0.21%	0.04%	0.30%	1.35%	1.50%	0.49%	0.00%	0.00%
VIIIX Vanguard Institutional Index Fund Institutional Plus Shares	2.41%	2.11%	3.66%	2.66%	3.39%	4.79%	3.07%	2.86%	2.45%	1.84%	2.38%	2.47%

Frequently Asked Questions

Can I hold both MUOIX and VIIIX in my portfolio?

With a correlation of 0.92, MUOIX and VIIIX 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, MUOIX or VIIIX?

MUOIX has higher volatility (3.21%) compared to VIIIX (2.83%). In terms of maximum drawdown, MUOIX dropped -38.35% vs VIIIX's -55.18%.

Which has better risk-adjusted returns?

VIIIX currently has the higher Sharpe Ratio (2.52 vs 1.37), 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.