At a glance
CPSO charges 0.69% a year, below the 0.86% average of the 7 funds most like it (the cheapest of 8). It has $26.6M in assets, the 8th largest of that group. Over the past year it returned +5.7% with distributions reinvested (S&P 500: +11.5%), the weakest of those 8 funds.
The short version
Calamos S&P 500 Structured Alt Protection ETF – October (CPSO) holds FLEX options (customizable exchange-traded options) on the SPDR S&P 500 ETF Trust (SPY). They aim to protect against 100% of SPY's price losses, before fees, over each one-year period starting October 1. The trade-off: gains are capped (6.40% before fees for the year to September 30, 2026), and SPY's dividends are left out. At 0.69%, it is the cheapest of eight loss-limiting (buffer) funds compared.
Price history
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CPSO +5.7% over the year to Oct 27, 2026, total return with distributions reinvested.
How it has behaved
| YTD | 1 yr | 3 yr | 5 yr | 10 yr | Since start | |
|---|---|---|---|---|---|---|
| CPSO price data to Oct 27, 2026 | +5.3% | +5.7% | — | — | — | +6.0% |
- Over the year to Oct 27, 2026, CPSO returned +5.7%, 8th of 8 among similar funds.
- Its worst full calendar year was 2025 (+6.2%); its best was 2025 (+6.2%).
- The deepest fall in its price history was 3.2% (Feb 19, 2025 to Apr 7, 2025), recovered by May 15, 2025.
Show as a table
| Year | Price data |
|---|---|
| 2026 (to date) | +5.3% |
| 2025 | +6.2% |
| 2008 financial crisis stocks fell Oct 9, 2007 – Mar 9, 2009 | Before this security existed |
|---|---|
| 2020 COVID crash stocks fell Feb 19, 2020 – Mar 23, 2020 | Before this security existed |
| 2022 bear market stocks fell Jan 3, 2022 – Oct 12, 2022 | Before this security existed |
What's inside
As of Jul 31, 2026, the fund held 0 securities; the ten largest made up 0% of assets.
| Holding | Weight |
|---|
By country
By asset type
What changed recently
- Over the three months to Jul 31, 2026, investors added a net $0.00 (creations minus redemptions, per the N-PORT report).
- Monthly total returns reported for that quarter: +0.87%, +0.25%, +0.43%.
How it works
CPSO is an actively managed ETF that does not pick stocks. It puts substantially all its assets into FLEX options. These are exchange-traded option contracts with customized strike (exercise) prices and expiration dates. They are tied to the SPDR S&P 500 ETF Trust (SPY), which holds the stocks in the S&P 500 Index. SPY's dividends are not part of the fund's return.
As of July 31, 2026, the fund held three options, all expiring September 30, 2026. A call option with a $4.60 strike, worth about 106% of net assets, moved almost in step with SPY. A put option at $666.18 guarded against losses below that level. A call option the fund sold at $708.82 gave away gains above the cap. For October 1, 2025 through September 30, 2026, the cap was 6.40% and the protection 100%, both before fees. After fees, they were 5.71% and 99.31%.
Each outcome period lasts about one year. At the end, the options settle in cash and the fund rolls into new ones. The cap resets based on market conditions, while the 100% protection level stays the same. Both are measured from the fund's share value on the first day and apply only at the end of the period. Investors who get in later or exit early can see very different results. Mid-period dips happen: the share price fell 3.2% from February 19 to April 7, 2025.
What it really costs
- CPSO charges 0.69% a year, versus an average of 0.86% for the similar funds below (1st of 8, cheapest first).
- Using the prospectus's standard example, $10,000 invested would cost about $70 in the first year and $859 over 10 years (assuming a 5% annual return).
| Cost of $10,000 (SEC example) | 1 yr | 3 yrs | 5 yrs | 10 yrs |
|---|---|---|---|---|
| CPSO | $70 | $221 | $384 | $859 |
Structure and tax notes
- Organized as a unit investment trust: it cannot lend out its securities or reinvest dividends between payouts, which can create a small drag versus similar open-end ETFs.
- Uses options to limit losses within a range (the buffer) in exchange for a cap on gains over each outcome period; results depend on when you buy relative to the period start.
In a retirement portfolio
It seeks to absorb 100% of SPY's price losses over each one-year outcome period, before fees, in exchange for capped gains and no dividends.
CPSO launched October 1, 2024, so it has no record from the 2008 financial crisis, the 2020 COVID crash or the 2022 bear market. Its only full calendar year, 2025, returned 6.24%. Its deepest drop was 3.2%, from February 19 to April 7, 2025, and it had recovered by May 15, 2025. That dip was shallow for anyone drawing cash, but the full protection applies only at the end of each period. The fund has no distributions on record, so spending money would have to come from trimming shares.
Costs are 0.69% a year, below the 0.86% average of seven buffer funds. In the SEC's standard example, that comes to $70 in the first year and $859 over 10 years on $10,000. The trade-off is limited upside: the one-year return was 5.7% as of October 27, 2026, last of eight buffer funds. Past results don't predict future ones, and a plan should look at the whole portfolio, not one fund.
Who it may suit — and who should look elsewhere
May suit
- Investors who want S&P 500 price exposure with 100% downside protection, before fees, over each October-to-September period, and who accept capped gains.
- Investors able to put money in on October 1 and stay until September 30, since the cap and protection apply only over the full period.
- Cost-conscious investors comparing defined-outcome ETFs: CPSO's 0.69% expense ratio is below the 0.86% average of seven similar buffer funds.
Look elsewhere if
- Anyone seeking income: the fund has no distributions on record, and its returns leave out the dividends SPY pays.
- Investors seeking fuller stock-market gains: CPSO's 5.7% one-year return ranked last of eight buffer funds compared, as of October 27, 2026.
- Those wary of very small funds: CPSO held $26.6 million in net assets on July 31, 2026, the smallest of eight buffer funds compared.
Close alternatives
Matched by other buffer (defined-outcome) funds, largest first.
| Fund | Cost | Net assets | 1 yr | 3 yr |
|---|---|---|---|---|
| CPSO this fund | 0.69% | $26.6M | +5.7% | — |
| BUFR FT Vest Laddered Buffer ETF | 0.95% | $10.49B | +11.6% | +16.8% |
| BUFD FT Vest Laddered Deep Buffer ETF | 0.95% | $2.04B | +9.5% | +13.9% |
| PJAN Innovator U.S. Equity Power Buffer ETF - Ja… | 0.79% | $1.44B | +10.5% | +14.8% |
| PDEC Innovator U.S. Equity Power Buffer ETF - De… | 0.79% | $984.1M | +11.6% | +14.9% |
| FDEC FT Vest US Equity Buffer ETF - December | 0.85% | $1.31B | +12.9% | +18.5% |
| FJAN FT Vest US Equity Buffer ETF - January | 0.85% | $1.47B | +12.3% | +17.4% |
| FFEB FT Vest U.S. Equity Buffer Fund - February | 0.85% | $1.42B | +12.9% | +18.6% |
Questions investors ask
Is CPSO good for retirement?
It may suit retirees who care more about protecting what they have than growing it. CPSO seeks to absorb 100% of SPY's price losses, before fees, for investors who hold for a full October-to-September period. Gains were capped at 6.40% before fees for the period ending September 30, 2026. One-year volatility (how much returns swing) was 2.2% as of October 27, 2026. Drawbacks: no distributions, returns that leave out SPY's dividends, and limited upside.
Can you lose money in CPSO?
Yes. The 100% protection is measured before fees. After the 0.69% expense ratio, it was 99.31% for October 1, 2025 through September 30, 2026, and brokerage commissions or taxes can reduce it further. It also applies only to investors who hold from the first day of a one-year outcome period to the last. In between, the price can fall: it dropped 3.2% from February 19 to April 7, 2025. Someone who invests mid-period after SPY has risen can lose ground back to the starting level.
When does CPSO reset its cap?
Each October, when a new outcome period of about one year begins and the fund rolls into new FLEX options. The new cap depends on market conditions at that moment, while protection stays at 100% before fees. For October 1, 2025 through September 30, 2026, the cap was 6.40% before fees and 5.71% after. About a week before each period ends, the fund's website posts the expected cap range for the next one.
Does CPSO pay dividends?
No. The fund has no distributions on record. Its returns are based only on SPY's share price, so the dividends paid by the S&P 500 companies inside SPY are left out. That is an easy-to-miss cost compared with owning SPY directly, on top of the 0.69% expense ratio. Investors who need regular income would have to raise cash by trimming shares, or may prefer to compare funds built to pay income.
What's the difference between CPSO and BUFR?
FT Vest Laddered Buffer ETF (BUFR) charges more, earned more over the year to October 27, 2026, and is built differently. CPSO seeks to absorb 100% of SPY's price losses over one October-to-September period, with capped gains. BUFR spreads its money across buffer series that start in different months, so its protection terms differ. BUFR's one-year return was 11.6%, against 5.7% for CPSO. Its expense ratio is 0.95%, against 0.69%. BUFR held $10.5 billion in net assets on August 31, 2026; CPSO held $26.6 million on July 31, 2026.