CPST vs. APXM

Last updated Jun 3, 2026

CPST (Calamos S&P 500 Structured Alt Protection ETF - September) and APXM (FT Vest U.S. Equity Max Buffer ETF - April) are both Defined Outcome funds. CPST is passively managed, while APXM is actively managed. Over the past year, CPST returned 7.84% vs 5.56% for APXM. A 0.69 correlation means they provide meaningful diversification when combined. CPST charges 0.69%/yr vs 0.85%/yr for APXM.

Performance

CPST vs. APXM - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Calamos S&P 500 Structured Alt Protection ETF - September (CPST) and FT Vest U.S. Equity Max Buffer ETF - April (APXM). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, CPST achieves a 2.67% return, which is significantly higher than APXM's 2.17% return.

CPST

• 1D: 0.07%
• 1M: 0.82%
• YTD: 2.67%
• 6M: 3.20%
• 1Y: 7.84%
• 3Y*: —
• 5Y*: —
• 10Y*: —

APXM

• 1D: 0.05%
• 1M: 0.73%
• YTD: 2.17%
• 6M: 2.70%
• 1Y: 5.56%
• 3Y*: —
• 5Y*: —
• 10Y*: —

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

CPST vs. APXM - Yearly Performance Comparison

	2026 (YTD)	2025
CPST Calamos S&P 500 Structured Alt Protection ETF - September	2.67%	9.27%
APXM FT Vest U.S. Equity Max Buffer ETF - April	2.17%	5.40%

Correlation

The correlation between CPST and APXM is 0.68, 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	0.68
Correlation (All Time) Calculated using the full available price history since Apr 22, 2025	0.69

The correlation between CPST and APXM has been stable across timeframes, ranging from 0.68 to 0.69 - a consistent structural relationship.

Return for Risk

CPST vs. APXM — Risk / Return Rank

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

CPST

CPST Risk / Return Rank: 94
CPST Sharpe Ratio Rank: 94
CPST Sortino Ratio Rank: 97
CPST Omega Ratio Rank: 96
CPST Calmar Ratio Rank: 90
CPST Martin Ratio Rank: 95

APXM

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

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.

CPST vs. APXM - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Calamos S&P 500 Structured Alt Protection ETF - September (CPST) and FT Vest U.S. Equity Max Buffer ETF - April (APXM). 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.

	CPST	APXM	Difference
Sharpe ratio Return per unit of total volatility	3.66	5.56	-1.90
Sortino ratio Return per unit of downside risk	6.09	10.77	-4.68
Omega ratio Gain probability vs. loss probability	1.84	2.65	-0.80
Calmar ratio Return relative to maximum drawdown	5.58	20.92	-15.34
Martin ratio Return relative to average drawdown	30.14	114.61	-84.47
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

CPST vs. APXM - Sharpe Ratio Comparison

The current CPST Sharpe Ratio is 3.66, which is lower than the APXM Sharpe Ratio of 5.56. The chart below compares the historical Sharpe Ratios of CPST and APXM, 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

	CPST	APXM	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	3.66	5.56	-1.90
Sharpe Ratio (All Time) Calculated using the full available price history	2.02	5.78	-3.76

Drawdowns

CPST vs. APXM - Drawdown Comparison

The maximum CPST drawdown since its inception was -3.79%, which is greater than APXM's maximum drawdown of -0.40%. Use the drawdown chart below to compare losses from any high point for CPST and APXM.

Drawdown Indicators

	CPST	APXM	Difference
Max Drawdown Largest peak-to-trough decline	-3.79%	-0.40%	-3.39%
Max Drawdown (1Y) Largest decline over 1 year	-1.42%	-0.27%	-1.15%
Current Drawdown Current decline from peak	0.00%	0.00%	0.00%
Average Drawdown Average peak-to-trough decline	-0.35%	-0.03%	-0.32%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.26%	0.05%	+0.21%

Volatility

CPST vs. APXM - Volatility Comparison

The current volatility for Calamos S&P 500 Structured Alt Protection ETF - September (CPST) is 0.32%, while FT Vest U.S. Equity Max Buffer ETF - April (APXM) has a volatility of 0.44%. This indicates that CPST experiences smaller price fluctuations and is considered to be less risky than APXM based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	CPST	APXM	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.32%	0.44%	-0.12%
Volatility (6M) Calculated over the trailing 6-month period	1.60%	0.77%	+0.83%
Volatility (1Y) Calculated over the trailing 1-year period	2.15%	1.01%	+1.14%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	3.37%	1.20%	+2.17%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	3.37%	1.20%	+2.17%

CPST vs. APXM - Expense Ratio Comparison

CPST has a 0.69% expense ratio, which is lower than APXM's 0.85% expense ratio.

Dividends

CPST vs. APXM - Dividend Comparison

Neither CPST nor APXM has paid dividends to shareholders.

Tickers have no history of dividend payments

Frequently Asked Questions

Can I hold both CPST and APXM in my portfolio?

CPST and APXM have a correlation of 0.68, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, CPST or APXM?

APXM has higher volatility (0.44%) compared to CPST (0.32%). In terms of maximum drawdown, CPST dropped -3.79% vs APXM's -0.40%.

Which ETF is better, CPST or APXM?

On 1-year performance, CPST leads with 7.84% vs 5.56% for APXM. On fees, CPST is cheaper at 0.69% per year. On volatility, CPST has been the lower-risk option at 0.32%. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF has performed better, CPST or APXM?

Over the 1-year period, CPST has performed better with a 7.84% return vs 5.56%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, CPST or APXM?

CPST is cheaper with a 0.69% expense ratio, compared with 0.85% for APXM.

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

CPST and APXM have nearly identical dividend yields, around 0.00%.

What is the main difference between CPST and APXM?

They also come from different issuers: Calamos and First Trust. Their fees differ too: 0.69% for CPST and 0.85% for APXM.

Which has better risk-adjusted returns?

APXM currently has the higher Sharpe Ratio (5.56 vs 3.66), 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.