RSPA vs. CPST

Last updated Jun 26, 2026

RSPA (Invesco S&P 500 Equal Weight Income Advantage ETF) and CPST (Calamos S&P 500 Structured Alt Protection ETF - September) are both exchange-traded funds - RSPA is a S&P 500 fund tracking the S&P 500 Equal Weight Index, while CPST is a Defined Outcome fund tracking the MerQube Cap Protect US Lrg Cap PR Index - Sep. Both are passively managed. Over the past year, RSPA returned 19.05% vs 6.65% for CPST. A 0.67 correlation means they provide meaningful diversification when combined. RSPA charges 0.29%/yr vs 0.69%/yr for CPST.

Performance

RSPA vs. CPST - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Invesco S&P 500 Equal Weight Income Advantage ETF (RSPA) and Calamos S&P 500 Structured Alt Protection ETF - September (CPST). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, RSPA achieves a 9.65% return, which is significantly higher than CPST's 2.61% return.

RSPA

• 1D: 0.51%
• 1M: 2.22%
• YTD: 9.65%
• 6M: 8.73%
• 1Y: 19.05%
• 3Y*: —
• 5Y*: —
• 10Y*: —

CPST

• 1D: -0.07%
• 1M: 0.11%
• YTD: 2.61%
• 6M: 2.46%
• 1Y: 6.65%
• 3Y*: —
• 5Y*: —
• 10Y*: —

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

RSPA vs. CPST - Yearly Performance Comparison

	2026 (YTD)	2025	2024
RSPA Invesco S&P 500 Equal Weight Income Advantage ETF	9.65%	11.07%	1.59%
CPST Calamos S&P 500 Structured Alt Protection ETF - September	2.61%	6.73%	1.97%

Correlation

The correlation between RSPA and CPST is 0.61, 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	0.61
Correlation (All Time) Calculated using the full available price history since Sep 3, 2024	0.67

The correlation between RSPA and CPST has been stable across timeframes, ranging from 0.61 to 0.67 - a consistent structural relationship.

Return for Risk

RSPA vs. CPST — Risk / Return Rank

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

RSPA

RSPA Risk / Return Rank: 73
RSPA Sharpe Ratio Rank: 73
RSPA Sortino Ratio Rank: 74
RSPA Omega Ratio Rank: 70
RSPA Calmar Ratio Rank: 71
RSPA Martin Ratio Rank: 75

CPST

CPST Risk / Return Rank: 94
CPST Sharpe Ratio Rank: 95
CPST Sortino Ratio Rank: 97
CPST Omega Ratio Rank: 96
CPST Calmar Ratio Rank: 89
CPST 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.

RSPA vs. CPST - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Invesco S&P 500 Equal Weight Income Advantage ETF (RSPA) and Calamos S&P 500 Structured Alt Protection ETF - September (CPST). 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.

	RSPA	CPST	Difference
Sharpe ratio: Return per unit of total volatility	2.01	3.25	-1.23
Sortino ratio: Return per unit of downside risk	2.87	5.28	-2.41
Omega ratio: Gain probability vs. loss probability	1.36	1.72	-0.36
Calmar ratio: Return relative to maximum drawdown	3.08	4.70	-1.62
Martin ratio: Return relative to average drawdown	12.27	25.30	-13.03

RSPA vs. CPST - Sharpe Ratio Comparison

The current RSPA Sharpe Ratio is 2.01, which is lower than the CPST Sharpe Ratio of 3.25. The chart below compares the historical Sharpe Ratios of RSPA and CPST, 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

RSPA vs. CPST - Drawdown Comparison

The maximum RSPA drawdown since its inception was -15.37%, which is greater than CPST's maximum drawdown of -3.79%. Use the drawdown chart below to compare losses from any high point for RSPA and CPST.

Drawdown Indicators

	RSPA	CPST	Difference
Max Drawdown Largest peak-to-trough decline	-15.37%	-3.79%	-11.58%
Max Drawdown (1Y) Largest decline over 1 year	-6.21%	-1.42%	-4.79%
Current Drawdown Current decline from peak	0.00%	-0.22%	+0.22%
Average Drawdown Average peak-to-trough decline	-2.00%	-0.34%	-1.66%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.56%	0.26%	+1.30%

Volatility

RSPA vs. CPST - Volatility Comparison

Invesco S&P 500 Equal Weight Income Advantage ETF (RSPA) has a higher volatility of 2.73% compared to Calamos S&P 500 Structured Alt Protection ETF - September (CPST) at 0.45%. This indicates that RSPA's price experiences larger fluctuations and is considered to be riskier than CPST based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	RSPA	CPST	Difference
Volatility (1M) Calculated over the trailing 1-month period	2.73%	0.45%	+2.28%
Volatility (6M) Calculated over the trailing 6-month period	7.00%	1.60%	+5.40%
Volatility (1Y) Calculated over the trailing 1-year period	9.51%	2.06%	+7.45%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	12.92%	3.33%	+9.59%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	12.92%	3.33%	+9.59%

RSPA vs. CPST - Expense Ratio Comparison

RSPA has a 0.29% expense ratio, which is lower than CPST's 0.69% expense ratio.

Dividends

RSPA vs. CPST - Dividend Comparison

RSPA's dividend yield for the trailing twelve months is around 8.95%, while CPST has not paid dividends to shareholders.

Position	TTM	2025	2024
CPST Calamos S&P 500 Structured Alt Protection ETF - September	0.00%	0.00%	0.00%
RSPA Invesco S&P 500 Equal Weight Income Advantage ETF	8.95%	9.14%	4.03%

Frequently Asked Questions

Can I hold both RSPA and CPST in my portfolio?

RSPA and CPST have a correlation of 0.61, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, RSPA or CPST?

RSPA has higher volatility (2.73%) compared to CPST (0.45%). In terms of maximum drawdown, RSPA dropped -15.37% vs CPST's -3.79%.

Which ETF is better, RSPA or CPST?

On 1-year performance, RSPA leads with 19.05% vs 6.65% for CPST. On fees, RSPA is cheaper at 0.29% per year. On volatility, CPST has been the lower-risk option at 0.45%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, RSPA or CPST?

Over the 1-year period, RSPA has performed better with a 19.05% return vs 6.65%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, RSPA or CPST?

RSPA is cheaper with a 0.29% expense ratio, compared with 0.69% for CPST.

Which ETF pays a higher dividend yield, RSPA or CPST?

RSPA has the higher dividend yield at 8.95%, compared with 0.00% for CPST.

What is the main difference between RSPA and CPST?

RSPA is categorized as S&P 500, while CPST is Defined Outcome. RSPA tracks S&P 500 Equal Weight Index, while CPST tracks MerQube Cap Protect US Lrg Cap PR Index - Sep. They also come from different issuers: Invesco and Calamos. Their fees differ too: 0.29% for RSPA and 0.69% for CPST.

Which has better risk-adjusted returns?

CPST currently has the higher Sharpe Ratio (3.25 vs 2.01), 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.