OWMBX vs. OWNYX

Last updated Jun 23, 2026

OWMBX (Old Westbury Municipal Bond Fund) and OWNYX (Old Westbury New York Municipal Bond Fund) are both Municipal Bonds funds from Old Westbury. Over the past 5 years, OWMBX returned 0.66%/yr vs 0.87%/yr for OWNYX. Their correlation of 0.86 suggests significant overlap in exposure. Both charge a 0.57% expense ratio.

Performance

OWMBX vs. OWNYX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Old Westbury Municipal Bond Fund (OWMBX) and Old Westbury New York Municipal Bond Fund (OWNYX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

As of year-to-date, both investments have demonstrated similar returns, with OWMBX at 0.57% and OWNYX at 0.57%.

OWMBX

• 1D: 0.09%
• 1M: 0.99%
• YTD: 0.57%
• 6M: 0.74%
• 1Y: 4.15%
• 3Y*: 2.73%
• 5Y*: 0.66%
• 10Y*: 1.39%

OWNYX

• 1D: 0.10%
• 1M: 0.80%
• YTD: 0.57%
• 6M: 0.78%
• 1Y: 4.00%
• 3Y*: 2.87%
• 5Y*: 0.87%
• 10Y*: —

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

OWMBX vs. OWNYX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018
OWMBX Old Westbury Municipal Bond Fund	0.57%	4.29%	0.43%	4.03%	-5.39%	-0.63%	5.01%	5.58%	0.99%
OWNYX Old Westbury New York Municipal Bond Fund	0.57%	4.64%	0.45%	4.24%	-5.03%	-0.31%	3.74%	4.95%	0.68%

Correlation

The correlation between OWMBX and OWNYX is 0.79, 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	0.79
Correlation (3Y) Calculated over the trailing 3-year period	0.88
Correlation (5Y) Calculated over the trailing 5-year period	0.89
Correlation (All Time) Calculated using the full available price history since Dec 3, 2018	0.86

The correlation between OWMBX and OWNYX has been stable across timeframes, ranging from 0.79 to 0.89 - a consistent structural relationship.

Return for Risk

OWMBX vs. OWNYX — Risk / Return Rank

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

OWMBX

OWMBX Risk / Return Rank: 62
OWMBX Sharpe Ratio Rank: 81
OWMBX Sortino Ratio Rank: 82
OWMBX Omega Ratio Rank: 92
OWMBX Calmar Ratio Rank: 29
OWMBX Martin Ratio Rank: 23

OWNYX

OWNYX Risk / Return Rank: 61
OWNYX Sharpe Ratio Rank: 79
OWNYX Sortino Ratio Rank: 82
OWNYX Omega Ratio Rank: 90
OWNYX Calmar Ratio Rank: 30
OWNYX Martin Ratio Rank: 24

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.

OWMBX vs. OWNYX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Old Westbury Municipal Bond Fund (OWMBX) and Old Westbury New York Municipal Bond Fund (OWNYX). 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.

	OWMBX	OWNYX	Difference
Sharpe ratio: Return per unit of total volatility	2.46	2.39	+0.06
Sortino ratio: Return per unit of downside risk	3.60	3.55	+0.05
Omega ratio: Gain probability vs. loss probability	1.66	1.62	+0.04
Calmar ratio: Return relative to maximum drawdown	1.91	1.95	-0.04
Martin ratio: Return relative to average drawdown	5.21	5.45	-0.24

OWMBX vs. OWNYX - Sharpe Ratio Comparison

The current OWMBX Sharpe Ratio is 2.46, which is comparable to the OWNYX Sharpe Ratio of 2.39. The chart below compares the historical Sharpe Ratios of OWMBX and OWNYX, 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

OWMBX vs. OWNYX - Drawdown Comparison

The maximum OWMBX drawdown since its inception was -9.54%, which is greater than OWNYX's maximum drawdown of -8.98%. Use the drawdown chart below to compare losses from any high point for OWMBX and OWNYX.

Drawdown Indicators

	OWMBX	OWNYX	Difference
Max Drawdown Largest peak-to-trough decline	-9.54%	-8.98%	-0.56%
Max Drawdown (1Y) Largest decline over 1 year	-2.45%	-2.30%	-0.15%
Max Drawdown (3Y) Largest decline over 3 years	-3.81%	-3.64%	-0.17%
Max Drawdown (5Y) Largest decline over 5 years	-9.37%	-8.98%	-0.39%
Max Drawdown (10Y) Largest decline over 10 years	-9.44%	—	—
Current Drawdown Current decline from peak	-1.05%	-1.02%	-0.03%
Average Drawdown Average peak-to-trough decline	-1.64%	-2.09%	+0.45%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.85%	0.78%	+0.07%

Volatility

OWMBX vs. OWNYX - Volatility Comparison

Old Westbury Municipal Bond Fund (OWMBX) and Old Westbury New York Municipal Bond Fund (OWNYX) have volatilities of 0.38% and 0.38%, respectively, indicating that both stocks experience similar levels of price fluctuations. This suggests that the risk associated with both stocks, as measured by volatility, is nearly the same. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	OWMBX	OWNYX	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.38%	0.38%	0.00%
Volatility (6M) Calculated over the trailing 6-month period	1.45%	1.41%	+0.04%
Volatility (1Y) Calculated over the trailing 1-year period	1.90%	1.88%	+0.02%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	3.11%	3.07%	+0.04%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	3.04%	3.28%	-0.24%

OWMBX vs. OWNYX - Expense Ratio Comparison

Both OWMBX and OWNYX have an expense ratio of 0.57%.

Dividends

OWMBX vs. OWNYX - Dividend Comparison

OWMBX's dividend yield for the trailing twelve months is around 2.60%, more than OWNYX's 2.41% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
OWMBX Old Westbury Municipal Bond Fund	2.60%	2.61%	2.54%	2.01%	1.15%	2.06%	2.55%	1.68%	1.45%	1.18%	1.61%	1.40%
OWNYX Old Westbury New York Municipal Bond Fund	2.41%	2.88%	2.40%	1.99%	1.29%	1.41%	1.76%	1.60%	0.08%	0.00%	0.00%	0.00%

Frequently Asked Questions

Can I hold both OWMBX and OWNYX in my portfolio?

OWMBX and OWNYX have a correlation of 0.79, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, OWMBX or OWNYX?

OWNYX has higher volatility (0.38%) compared to OWMBX (0.38%). In terms of maximum drawdown, OWMBX dropped -9.54% vs OWNYX's -8.98%.

Which has better risk-adjusted returns?

OWMBX currently has the higher Sharpe Ratio (2.46 vs 2.39), 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.