CPSM vs. OCTB

Last updated Jun 4, 2026

CPSM (Calamos S&P 500 Structured Alt Protection ETF - May) and OCTB (Aptus October Buffer ETF) are both Defined Outcome funds. Both are actively managed. A 0.65 correlation means they provide meaningful diversification when combined. CPSM charges 0.69%/yr vs 0.25%/yr for OCTB.

Performance

CPSM vs. OCTB - Performance Comparison

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

Returns By Period

In the year-to-date period, CPSM achieves a 2.27% return, which is significantly lower than OCTB's 6.18% return.

CPSM

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

OCTB

• 1D: -0.17%
• 1M: 2.41%
• YTD: 6.18%
• 6M: 6.75%
• 1Y: —
• 3Y*: —
• 5Y*: —
• 10Y*: —

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

CPSM vs. OCTB - Yearly Performance Comparison

	2026 (YTD)	2025
CPSM Calamos S&P 500 Structured Alt Protection ETF - May	2.27%	1.12%
OCTB Aptus October Buffer ETF	6.18%	2.37%

Correlation

The correlation between CPSM and OCTB is 0.65, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (All Time) Calculated using the full available price history since Oct 15, 2025	0.65

Return for Risk

CPSM vs. OCTB — Risk / Return Rank

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

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.

CPSM vs. OCTB - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Calamos S&P 500 Structured Alt Protection ETF - May (CPSM) and Aptus October Buffer ETF (OCTB). 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.

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

Sharpe Ratios by Period

	CPSM	OCTB	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	3.78	—	—
Sharpe Ratio (All Time) Calculated using the full available price history	1.54	1.97	-0.43

Drawdowns

CPSM vs. OCTB - Drawdown Comparison

The maximum CPSM drawdown since its inception was -5.19%, which is greater than OCTB's maximum drawdown of -4.79%. Use the drawdown chart below to compare losses from any high point for CPSM and OCTB.

Drawdown Indicators

	CPSM	OCTB	Difference
Max Drawdown Largest peak-to-trough decline	-5.19%	-4.79%	-0.40%
Max Drawdown (1Y) Largest decline over 1 year	-0.45%	—	—
Current Drawdown Current decline from peak	-0.06%	-0.17%	+0.11%
Average Drawdown Average peak-to-trough decline	-0.20%	-0.70%	+0.50%
Ulcer Index Depth and duration of drawdowns from previous peaks	0.10%	—	—

Volatility

Volatility by Period

	CPSM	OCTB	Difference
Volatility (1M) Calculated over the trailing 1-month period	0.35%	—	—
Volatility (6M) Calculated over the trailing 6-month period	1.14%	—	—
Volatility (1Y) Calculated over the trailing 1-year period	1.57%	7.20%	-5.63%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	5.10%	7.20%	-2.10%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	5.10%	7.20%	-2.10%

CPSM vs. OCTB - Expense Ratio Comparison

CPSM has a 0.69% expense ratio, which is higher than OCTB's 0.25% expense ratio.

Dividends

CPSM vs. OCTB - Dividend Comparison

Neither CPSM nor OCTB has paid dividends to shareholders.

Tickers have no history of dividend payments

Frequently Asked Questions

Can I hold both CPSM and OCTB in my portfolio?

CPSM and OCTB have a correlation of 0.65, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which ETF is better, CPSM or OCTB?

On fees, OCTB is cheaper at 0.25% per year. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF is cheaper, CPSM or OCTB?

OCTB is cheaper with a 0.25% expense ratio, compared with 0.69% for CPSM.

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

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

What is the main difference between CPSM and OCTB?

They also come from different issuers: Calamos and Aptus Capital Advisors. Their fees differ too: 0.69% for CPSM and 0.25% for OCTB.