RBUF vs. CPSM

Last updated Jun 4, 2026

RBUF (Innovator U.S. Small Cap 10 Buffer ETF - Quarterly) and CPSM (Calamos S&P 500 Structured Alt Protection ETF - May) are both Defined Outcome funds. Both are actively managed. Over the past year, RBUF returned 15.41% vs 5.88% for CPSM. A 0.55 correlation means they provide meaningful diversification when combined. RBUF charges 0.79%/yr vs 0.69%/yr for CPSM.

Performance

RBUF vs. CPSM - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Innovator U.S. Small Cap 10 Buffer ETF - Quarterly (RBUF) and Calamos S&P 500 Structured Alt Protection ETF - May (CPSM). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, RBUF achieves a 6.49% return, which is significantly higher than CPSM's 2.27% return.

RBUF

• 1D: -0.03%
• 1M: 1.38%
• YTD: 6.49%
• 6M: 5.47%
• 1Y: 15.41%
• 3Y*: —
• 5Y*: —
• 10Y*: —

CPSM

• 1D: -0.06%
• 1M: 0.71%
• YTD: 2.27%
• 6M: 2.72%
• 1Y: 5.88%
• 3Y*: —
• 5Y*: —
• 10Y*: —

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

RBUF vs. CPSM - Yearly Performance Comparison

	2026 (YTD)	2025	2024
RBUF Innovator U.S. Small Cap 10 Buffer ETF - Quarterly	6.49%	10.88%	4.55%
CPSM Calamos S&P 500 Structured Alt Protection ETF - May	2.27%	7.21%	3.81%

Correlation

The correlation between RBUF and CPSM is 0.49, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.49
Correlation (All Time) Calculated using the full available price history since Jul 2, 2024	0.55

The correlation between RBUF and CPSM has been stable across timeframes, ranging from 0.49 to 0.55 - a consistent structural relationship.

Return for Risk

RBUF vs. CPSM — Risk / Return Rank

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

RBUF

RBUF Risk / Return Rank: 84
RBUF Sharpe Ratio Rank: 77
RBUF Sortino Ratio Rank: 82
RBUF Omega Ratio Rank: 83
RBUF Calmar Ratio Rank: 88
RBUF Martin Ratio Rank: 91

CPSM

CPSM Risk / Return Rank: 97
CPSM Sharpe Ratio Rank: 94
CPSM Sortino Ratio Rank: 97
CPSM Omega Ratio Rank: 96
CPSM Calmar Ratio Rank: 98
CPSM Martin Ratio Rank: 98

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.

RBUF vs. CPSM - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Innovator U.S. Small Cap 10 Buffer ETF - Quarterly (RBUF) and Calamos S&P 500 Structured Alt Protection ETF - May (CPSM). 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.

	RBUF	CPSM	Difference
Sharpe ratio: Return per unit of total volatility	2.48	3.78	-1.30
Sortino ratio: Return per unit of downside risk	3.62	6.33	-2.71
Omega ratio: Gain probability vs. loss probability	1.49	1.84	-0.34
Calmar ratio: Return relative to maximum drawdown	5.00	13.01	-8.01
Martin ratio: Return relative to average drawdown	21.18	61.11	-39.93
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

RBUF vs. CPSM - Sharpe Ratio Comparison

The current RBUF Sharpe Ratio is 2.48, which is lower than the CPSM Sharpe Ratio of 3.78. The chart below compares the historical Sharpe Ratios of RBUF and CPSM, 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

	RBUF	CPSM	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.48	3.78	-1.30
Sharpe Ratio (All Time) Calculated using the full available price history	1.33	1.54	-0.21

Drawdowns

RBUF vs. CPSM - Drawdown Comparison

The maximum RBUF drawdown since its inception was -11.36%, which is greater than CPSM's maximum drawdown of -5.19%. Use the drawdown chart below to compare losses from any high point for RBUF and CPSM.

Drawdown Indicators

	RBUF	CPSM	Difference
Max Drawdown Largest peak-to-trough decline	-11.36%	-5.19%	-6.17%
Max Drawdown (1Y) Largest decline over 1 year	-3.09%	-0.45%	-2.64%
Current Drawdown Current decline from peak	-0.03%	-0.06%	+0.03%
Average Drawdown Average peak-to-trough decline	-1.34%	-0.20%	-1.14%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.73%	0.10%	+0.63%

Volatility

RBUF vs. CPSM - Volatility Comparison

Innovator U.S. Small Cap 10 Buffer ETF - Quarterly (RBUF) has a higher volatility of 0.74% compared to Calamos S&P 500 Structured Alt Protection ETF - May (CPSM) at 0.35%. This indicates that RBUF's price experiences larger fluctuations and is considered to be riskier than CPSM based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	RBUF	CPSM	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.74%	0.35%	+0.39%
Volatility (6M) Calculated over the trailing 6-month period	4.11%	1.14%	+2.97%
Volatility (1Y) Calculated over the trailing 1-year period	6.27%	1.57%	+4.70%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	8.73%	5.10%	+3.63%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	8.73%	5.10%	+3.63%

RBUF vs. CPSM - Expense Ratio Comparison

RBUF has a 0.79% expense ratio, which is higher than CPSM's 0.69% expense ratio.

Dividends

RBUF vs. CPSM - Dividend Comparison

Neither RBUF nor CPSM has paid dividends to shareholders.

Tickers have no history of dividend payments

Frequently Asked Questions

Can I hold both RBUF and CPSM in my portfolio?

RBUF and CPSM have a correlation of 0.49, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, RBUF or CPSM?

RBUF has higher volatility (0.74%) compared to CPSM (0.35%). In terms of maximum drawdown, RBUF dropped -11.36% vs CPSM's -5.19%.

Which ETF is better, RBUF or CPSM?

On 1-year performance, RBUF leads with 15.41% vs 5.88% for CPSM. On fees, CPSM is cheaper at 0.69% per year. On volatility, CPSM has been the lower-risk option at 0.35%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, RBUF or CPSM?

Over the 1-year period, RBUF has performed better with a 15.41% return vs 5.88%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, RBUF or CPSM?

CPSM is cheaper with a 0.69% expense ratio, compared with 0.79% for RBUF.

Which ETF pays a higher dividend yield, RBUF or CPSM?

RBUF and CPSM have nearly identical dividend yields, around 0.00%.

What is the main difference between RBUF and CPSM?

They also come from different issuers: Innovator and Calamos. Their fees differ too: 0.79% for RBUF and 0.69% for CPSM.

Which has better risk-adjusted returns?

CPSM currently has the higher Sharpe Ratio (3.78 vs 2.48), 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.