BUFM vs. CPSP

Last updated Jun 4, 2026

BUFM (AB Moderate Buffer ETF) and CPSP (Calamos S&P 500 Structured Alt Protection ETF - April) are both exchange-traded funds - BUFM is a Defined Outcome fund actively managed by AllianceBernstein, while CPSP is a S&P 500 fund actively managed by Calamos. Both are actively managed. Over the past year, BUFM returned 12.60% vs 7.13% for CPSP. A 0.71 correlation means they provide meaningful diversification when combined. Both charge a 0.69% expense ratio.

Performance

BUFM vs. CPSP - Performance Comparison

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

Returns By Period

In the year-to-date period, BUFM achieves a 3.71% return, which is significantly higher than CPSP's 3.18% return.

BUFM

• 1D: -0.13%
• 1M: 2.19%
• YTD: 3.71%
• 6M: 4.16%
• 1Y: 12.60%
• 3Y*: —
• 5Y*: —
• 10Y*: —

CPSP

• 1D: 0.00%
• 1M: 0.60%
• YTD: 3.18%
• 6M: 3.74%
• 1Y: 7.13%
• 3Y*: —
• 5Y*: —
• 10Y*: —

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

BUFM vs. CPSP - Yearly Performance Comparison

	2026 (YTD)	2025
BUFM AB Moderate Buffer ETF	3.71%	12.27%
CPSP Calamos S&P 500 Structured Alt Protection ETF - April	3.18%	5.46%

Correlation

The correlation between BUFM and CPSP 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 2, 2025	0.71

The correlation between BUFM and CPSP has been stable across timeframes, ranging from 0.68 to 0.71 - a consistent structural relationship.

Return for Risk

BUFM vs. CPSP — Risk / Return Rank

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

BUFM

BUFM Risk / Return Rank: 67
BUFM Sharpe Ratio Rank: 68
BUFM Sortino Ratio Rank: 67
BUFM Omega Ratio Rank: 71
BUFM Calmar Ratio Rank: 63
BUFM Martin Ratio Rank: 64

CPSP

CPSP Risk / Return Rank: 98
CPSP Sharpe Ratio Rank: 98
CPSP Sortino Ratio Rank: 99
CPSP Omega Ratio Rank: 98
CPSP Calmar Ratio Rank: 98
CPSP 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.

BUFM vs. CPSP - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for AB Moderate Buffer ETF (BUFM) and Calamos S&P 500 Structured Alt Protection ETF - April (CPSP). 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.

	BUFM	CPSP	Difference
Sharpe ratio: Return per unit of total volatility	2.19	5.08	-2.88
Sortino ratio: Return per unit of downside risk	3.05	9.15	-6.10
Omega ratio: Gain probability vs. loss probability	1.42	2.31	-0.89
Calmar ratio: Return relative to maximum drawdown	3.11	19.11	-16.00
Martin ratio: Return relative to average drawdown	11.49	96.35	-84.86
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

BUFM vs. CPSP - Sharpe Ratio Comparison

The current BUFM Sharpe Ratio is 2.19, which is lower than the CPSP Sharpe Ratio of 5.08. The chart below compares the historical Sharpe Ratios of BUFM and CPSP, 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

	BUFM	CPSP	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.19	5.08	-2.88
Sharpe Ratio (All Time) Calculated using the full available price history	1.12	3.17	-2.05

Drawdowns

BUFM vs. CPSP - Drawdown Comparison

The maximum BUFM drawdown since its inception was -9.43%, which is greater than CPSP's maximum drawdown of -1.73%. Use the drawdown chart below to compare losses from any high point for BUFM and CPSP.

Drawdown Indicators

	BUFM	CPSP	Difference
Max Drawdown Largest peak-to-trough decline	-9.43%	-1.73%	-7.70%
Max Drawdown (1Y) Largest decline over 1 year	-4.07%	-0.37%	-3.70%
Current Drawdown Current decline from peak	-0.13%	0.00%	-0.13%
Average Drawdown Average peak-to-trough decline	-0.99%	-0.08%	-0.91%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.10%	0.07%	+1.03%

Volatility

BUFM vs. CPSP - Volatility Comparison

AB Moderate Buffer ETF (BUFM) has a higher volatility of 1.05% compared to Calamos S&P 500 Structured Alt Protection ETF - April (CPSP) at 0.32%. This indicates that BUFM's price experiences larger fluctuations and is considered to be riskier than CPSP based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	BUFM	CPSP	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.05%	0.32%	+0.73%
Volatility (6M) Calculated over the trailing 6-month period	4.37%	0.84%	+3.53%
Volatility (1Y) Calculated over the trailing 1-year period	5.77%	1.42%	+4.35%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	9.43%	2.37%	+7.06%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	9.43%	2.37%	+7.06%

BUFM vs. CPSP - Expense Ratio Comparison

Both BUFM and CPSP have an expense ratio of 0.69%.

Dividends

BUFM vs. CPSP - Dividend Comparison

Neither BUFM nor CPSP has paid dividends to shareholders.

Tickers have no history of dividend payments

Frequently Asked Questions

Can I hold both BUFM and CPSP in my portfolio?

BUFM and CPSP 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, BUFM or CPSP?

BUFM has higher volatility (1.05%) compared to CPSP (0.32%). In terms of maximum drawdown, BUFM dropped -9.43% vs CPSP's -1.73%.

Which ETF is better, BUFM or CPSP?

On 1-year performance, BUFM leads with 12.60% vs 7.13% for CPSP. Both ETFs have the same 0.69% expense ratio. On volatility, CPSP 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, BUFM or CPSP?

Over the 1-year period, BUFM has performed better with a 12.60% return vs 7.13%. Past performance does not guarantee future results, so compare this with risk, fees, and fund exposure.

Which ETF is cheaper, BUFM or CPSP?

BUFM and CPSP have the same expense ratio: 0.69% per year.

Which ETF pays a higher dividend yield, BUFM or CPSP?

BUFM and CPSP have nearly identical dividend yields, around 0.00%.

What is the main difference between BUFM and CPSP?

BUFM is categorized as Defined Outcome, while CPSP is S&P 500. They also come from different issuers: AllianceBernstein and Calamos.

Which has better risk-adjusted returns?

CPSP currently has the higher Sharpe Ratio (5.08 vs 2.19), 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.