CGUI vs. BUCK

Last updated Jun 4, 2026

CGUI (Capital Group Ultra Short Income ETF) and BUCK (Simplify Treasury Option Income ETF) are both exchange-traded funds - CGUI is a Ultrashort Bond fund actively managed by Capital Group, while BUCK is a Government Bonds fund actively managed by Simplify. Both are actively managed. Over the past year, CGUI returned 4.42% vs 7.95% for BUCK. At a 0.08 correlation, their price movements are largely independent. CGUI charges 0.18%/yr vs 0.35%/yr for BUCK.

Performance

CGUI vs. BUCK - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Capital Group Ultra Short Income ETF (CGUI) and Simplify Treasury Option Income ETF (BUCK). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, CGUI achieves a 1.50% return, which is significantly lower than BUCK's 1.90% return.

CGUI

• 1D: -0.04%
• 1M: 0.29%
• YTD: 1.50%
• 6M: 1.84%
• 1Y: 4.42%
• 3Y*: —
• 5Y*: —
• 10Y*: —

BUCK

• 1D: 0.02%
• 1M: 0.38%
• YTD: 1.90%
• 6M: 2.09%
• 1Y: 7.95%
• 3Y*: 5.27%
• 5Y*: —
• 10Y*: —

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

CGUI vs. BUCK - Yearly Performance Comparison

	2026 (YTD)	2025	2024
CGUI Capital Group Ultra Short Income ETF	1.50%	4.99%	3.03%
BUCK Simplify Treasury Option Income ETF	1.90%	4.13%	3.85%

Correlation

The correlation between CGUI and BUCK is 0.09, meaning there is essentially no relationship between their price movements. Each responds to its own set of market drivers, making them strong candidates for combining in a diversified portfolio.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.09
Correlation (All Time) Calculated using the full available price history since Jun 28, 2024	0.08

Return for Risk

CGUI vs. BUCK — Risk / Return Rank

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

CGUI

CGUI Risk / Return Rank: 99
CGUI Sharpe Ratio Rank: 98
CGUI Sortino Ratio Rank: 99
CGUI Omega Ratio Rank: 99
CGUI Calmar Ratio Rank: 99
CGUI Martin Ratio Rank: 99

BUCK

BUCK Risk / Return Rank: 87
BUCK Sharpe Ratio Rank: 77
BUCK Sortino Ratio Rank: 84
BUCK Omega Ratio Rank: 86
BUCK Calmar Ratio Rank: 92
BUCK Martin Ratio Rank: 95

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.

CGUI vs. BUCK - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Capital Group Ultra Short Income ETF (CGUI) and Simplify Treasury Option Income ETF (BUCK). 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.

	CGUI	BUCK	Difference
Sharpe ratio: Return per unit of total volatility	5.99	2.54	+3.45
Sortino ratio: Return per unit of downside risk	10.92	3.83	+7.09
Omega ratio: Gain probability vs. loss probability	2.66	1.54	+1.11
Calmar ratio: Return relative to maximum drawdown	24.99	6.11	+18.88
Martin ratio: Return relative to average drawdown	105.06	32.31	+72.74
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

CGUI vs. BUCK - Sharpe Ratio Comparison

The current CGUI Sharpe Ratio is 5.99, which is higher than the BUCK Sharpe Ratio of 2.54. The chart below compares the historical Sharpe Ratios of CGUI and BUCK, 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

	CGUI	BUCK	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	5.99	2.54	+3.45
Sharpe Ratio (All Time) Calculated using the full available price history	6.20	1.47	+4.73

Drawdowns

CGUI vs. BUCK - Drawdown Comparison

The maximum CGUI drawdown since its inception was -0.18%, smaller than the maximum BUCK drawdown of -5.43%. Use the drawdown chart below to compare losses from any high point for CGUI and BUCK.

Drawdown Indicators

	CGUI	BUCK	Difference
Max Drawdown Largest peak-to-trough decline	-0.18%	-5.43%	+5.25%
Max Drawdown (1Y) Largest decline over 1 year	-0.18%	-1.31%	+1.13%
Max Drawdown (3Y) Largest decline over 3 years	—	-5.43%	—
Current Drawdown Current decline from peak	-0.04%	-0.04%	0.00%
Average Drawdown Average peak-to-trough decline	-0.02%	-0.49%	+0.47%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.04%	0.25%	-0.21%

Volatility

CGUI vs. BUCK - Volatility Comparison

The current volatility for Capital Group Ultra Short Income ETF (CGUI) is 0.30%, while Simplify Treasury Option Income ETF (BUCK) has a volatility of 0.70%. This indicates that CGUI experiences smaller price fluctuations and is considered to be less risky than BUCK based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	CGUI	BUCK	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.30%	0.70%	-0.40%
Volatility (6M) Calculated over the trailing 6-month period	0.56%	1.53%	-0.97%
Volatility (1Y) Calculated over the trailing 1-year period	0.74%	3.14%	-2.40%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	0.80%	3.49%	-2.69%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	0.80%	3.49%	-2.69%

CGUI vs. BUCK - Expense Ratio Comparison

CGUI has a 0.18% expense ratio, which is lower than BUCK's 0.35% expense ratio.

Dividends

CGUI vs. BUCK - Dividend Comparison

CGUI's dividend yield for the trailing twelve months is around 3.89%, less than BUCK's 7.42% yield.

Position	TTM	2025	2024	2023	2022
BUCK Simplify Treasury Option Income ETF	7.42%	7.59%	8.84%	4.84%	0.59%
CGUI Capital Group Ultra Short Income ETF	3.89%	4.17%	2.62%	0.00%	0.00%

Frequently Asked Questions

Can I hold both CGUI and BUCK in my portfolio?

CGUI and BUCK have a correlation of 0.09, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, CGUI or BUCK?

BUCK has higher volatility (0.70%) compared to CGUI (0.30%). In terms of maximum drawdown, CGUI dropped -0.18% vs BUCK's -5.43%.

Which ETF is better, CGUI or BUCK?

On 1-year performance, BUCK leads with 7.95% vs 4.42% for CGUI. On fees, CGUI is cheaper at 0.18% per year. On volatility, CGUI has been the lower-risk option at 0.30%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, CGUI or BUCK?

Over the 1-year period, BUCK has performed better with a 7.95% return vs 4.42%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, CGUI or BUCK?

CGUI is cheaper with a 0.18% expense ratio, compared with 0.35% for BUCK.

Which ETF pays a higher dividend yield, CGUI or BUCK?

BUCK has the higher dividend yield at 7.42%, compared with 3.89% for CGUI.

What is the main difference between CGUI and BUCK?

CGUI is categorized as Ultrashort Bond, while BUCK is Government Bonds. They also come from different issuers: Capital Group and Simplify. Their fees differ too: 0.18% for CGUI and 0.35% for BUCK.

Which has better risk-adjusted returns?

CGUI currently has the higher Sharpe Ratio (5.99 vs 2.54), 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.