BWZ vs. IAGG

Last updated Jun 4, 2026

BWZ (SPDR Bloomberg Barclays Short Term International Treasury Bond ETF) and IAGG (iShares Core International Aggregate Bond ETF) are both exchange-traded funds - BWZ is a International Government Bonds fund tracking the Bloomberg Global Treasury (1-3 Y) Customized, while IAGG is a Global Bonds fund tracking the Bloomberg Global Aggregate ex USD 10% Issuer Capped (Hedged) Index. Both are passively managed. Over the past 10 years, BWZ returned -0.49%/yr vs 2.17%/yr for IAGG. At a 0.24 correlation, their price movements are largely independent. BWZ charges 0.35%/yr vs 0.07%/yr for IAGG.

Performance

BWZ vs. IAGG - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in SPDR Bloomberg Barclays Short Term International Treasury Bond ETF (BWZ) and iShares Core International Aggregate Bond ETF (IAGG). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, BWZ achieves a -0.62% return, which is significantly lower than IAGG's 0.92% return. Over the past 10 years, BWZ has underperformed IAGG with an annualized return of -0.49%, while IAGG has yielded a comparatively higher 2.17% annualized return.

BWZ

• 1D: -0.52%
• 1M: -0.85%
• YTD: -0.62%
• 6M: -0.00%
• 1Y: 0.04%
• 3Y*: 2.58%
• 5Y*: -2.01%
• 10Y*: -0.49%

IAGG

• 1D: -0.20%
• 1M: 0.66%
• YTD: 0.92%
• 6M: 0.72%
• 1Y: 2.30%
• 3Y*: 4.59%
• 5Y*: 1.11%
• 10Y*: 2.17%

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

BWZ vs. IAGG - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
BWZ SPDR Bloomberg Barclays Short Term International Treasury Bond ETF	-0.62%	10.47%	-5.31%	2.97%	-10.56%	-6.85%	6.47%	0.99%	-3.36%	10.18%
IAGG iShares Core International Aggregate Bond ETF	0.92%	3.26%	4.51%	8.49%	-10.86%	-1.87%	4.63%	7.99%	3.38%	2.09%

Correlation

The correlation between BWZ and IAGG is 0.46, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.46
Correlation (3Y) Calculated over the trailing 3-year period	0.39
Correlation (5Y) Calculated over the trailing 5-year period	0.36
Correlation (10Y) Calculated over the trailing 10-year period	0.26
Correlation (All Time) Calculated using the full available price history since Nov 13, 2015	0.24

Over the past year, BWZ and IAGG have become more correlated (0.46) than their long-term average of 0.24, meaning their price movements have been converging.

Return for Risk

BWZ vs. IAGG — Risk / Return Rank

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

BWZ

BWZ Risk / Return Rank: 8
BWZ Sharpe Ratio Rank: 9
BWZ Sortino Ratio Rank: 8
BWZ Omega Ratio Rank: 8
BWZ Calmar Ratio Rank: 9
BWZ Martin Ratio Rank: 9

IAGG

IAGG Risk / Return Rank: 22
IAGG Sharpe Ratio Rank: 23
IAGG Sortino Ratio Rank: 22
IAGG Omega Ratio Rank: 22
IAGG Calmar Ratio Rank: 22
IAGG Martin Ratio Rank: 23

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.

BWZ vs. IAGG - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for SPDR Bloomberg Barclays Short Term International Treasury Bond ETF (BWZ) and iShares Core International Aggregate Bond ETF (IAGG). 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.

	BWZ	IAGG	Difference
Sharpe ratio Return per unit of total volatility	0.01	0.81	-0.81
Sortino ratio Return per unit of downside risk	0.06	1.19	-1.13
Omega ratio Gain probability vs. loss probability	1.01	1.15	-0.14
Calmar ratio Return relative to maximum drawdown	0.01	1.00	-0.99
Martin ratio Return relative to average drawdown	0.02	2.99	-2.97
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

BWZ vs. IAGG - Sharpe Ratio Comparison

The current BWZ Sharpe Ratio is 0.01, which is lower than the IAGG Sharpe Ratio of 0.81. The chart below compares the historical Sharpe Ratios of BWZ and IAGG, 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

	BWZ	IAGG	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.01	0.81	-0.81
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	-0.27	0.25	-0.51
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	-0.07	0.54	-0.61
Sharpe Ratio (All Time) Calculated using the full available price history	-0.03	0.62	-0.64

Drawdowns

BWZ vs. IAGG - Drawdown Comparison

The maximum BWZ drawdown since its inception was -34.23%, which is greater than IAGG's maximum drawdown of -13.88%. Use the drawdown chart below to compare losses from any high point for BWZ and IAGG.

Drawdown Indicators

	BWZ	IAGG	Difference
Max Drawdown Largest peak-to-trough decline	-34.23%	-13.88%	-20.35%
Max Drawdown (1Y) Largest decline over 1 year	-5.15%	-2.32%	-2.83%
Max Drawdown (3Y) Largest decline over 3 years	-8.60%	-2.32%	-6.28%
Max Drawdown (5Y) Largest decline over 5 years	-23.58%	-13.57%	-10.01%
Max Drawdown (10Y) Largest decline over 10 years	-24.90%	-13.88%	-11.02%
Current Drawdown Current decline from peak	-22.39%	-0.98%	-21.41%
Average Drawdown Average peak-to-trough decline	-16.10%	-2.85%	-13.25%
Ulcer Index Depth and duration of drawdowns from previous peaks	2.25%	0.77%	+1.48%

Volatility

BWZ vs. IAGG - Volatility Comparison

SPDR Bloomberg Barclays Short Term International Treasury Bond ETF (BWZ) has a higher volatility of 1.83% compared to iShares Core International Aggregate Bond ETF (IAGG) at 1.18%. This indicates that BWZ's price experiences larger fluctuations and is considered to be riskier than IAGG based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	BWZ	IAGG	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.83%	1.18%	+0.65%
Volatility (6M) Calculated over the trailing 6-month period	4.97%	2.40%	+2.57%
Volatility (1Y) Calculated over the trailing 1-year period	6.93%	2.84%	+4.09%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	7.60%	4.51%	+3.09%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	6.95%	4.05%	+2.90%

BWZ vs. IAGG - Expense Ratio Comparison

BWZ has a 0.35% expense ratio, which is higher than IAGG's 0.07% expense ratio.

Dividends

BWZ vs. IAGG - Dividend Comparison

BWZ's dividend yield for the trailing twelve months is around 2.10%, less than IAGG's 3.66% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BWZ SPDR Bloomberg Barclays Short Term International Treasury Bond ETF	2.10%	2.05%	2.47%	1.63%	0.44%	0.60%	0.13%	0.43%	1.10%	0.40%	0.13%	0.06%
IAGG iShares Core International Aggregate Bond ETF	3.66%	3.08%	4.28%	3.55%	2.27%	1.16%	1.95%	2.82%	3.02%	1.74%	1.56%	0.13%

Frequently Asked Questions

Can I hold both BWZ and IAGG in my portfolio?

BWZ and IAGG have a correlation of 0.46, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, BWZ or IAGG?

BWZ has higher volatility (1.83%) compared to IAGG (1.18%). In terms of maximum drawdown, BWZ dropped -34.23% vs IAGG's -13.88%.

Which ETF is better, BWZ or IAGG?

On 10-year performance, IAGG leads with 2.17% vs -0.49% for BWZ. On fees, IAGG is cheaper at 0.07% per year. On volatility, IAGG has been the lower-risk option at 1.18%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, BWZ or IAGG?

Over the 10-year period, IAGG has performed better with a 2.17% return vs -0.49%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, BWZ or IAGG?

IAGG is cheaper with a 0.07% expense ratio, compared with 0.35% for BWZ.

Which ETF pays a higher dividend yield, BWZ or IAGG?

IAGG has the higher dividend yield at 3.66%, compared with 2.10% for BWZ.

What is the main difference between BWZ and IAGG?

BWZ is categorized as International Government Bonds, while IAGG is Global Bonds. BWZ tracks Bloomberg Global Treasury (1-3 Y) Customized, while IAGG tracks Bloomberg Global Aggregate ex USD 10% Issuer Capped (Hedged) Index. They also come from different issuers: State Street and iShares. Their fees differ too: 0.35% for BWZ and 0.07% for IAGG.

Which has better risk-adjusted returns?

IAGG currently has the higher Sharpe Ratio (0.81 vs 0.01), 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.