CPST vs SIXO: which one stands where?
As of Oct 1, 2026 SIXO can fall 0.4% before its buffer engages and CPST 0.1%, and SIXO resets 153 days sooner. Calamos S&P 500 ® Structured Alt Protection ETF - September and AllianzIM U.S. Equity Buffer10 ETF - Apr.
CPST: reference +0.1% since period start, fund 0.0%; buffer −0 to floor; cap +8.0%; Full floor.
SIXO: reference 0.0% since period start, fund 0.0%; buffer 0 to −10; cap +7.7%; Between buffer and cap.
These are two different products. CPST is a floor fund, which caps how far a holder can fall. SIXO is a buffer fund, which absorbs the first part of a fall and leaves everything below it with the holder.
They do not reset together. SIXO has 182 days of its period left and CPST has 335, so the two are not the same bet on the same months.
Where each one stands today
SIXO resets first, on Mar 31, 2027, 182 days from now; CPST runs to Sep 1, 2027, 335 days. A fall from here reaches CPST’s buffer after 0.1% and SIXO’s after 0.4%. Both track SPY, so what separates them is where each is in its own period.
Every figure is ETFIQ’s own, from the issuer’s published outcome-period terms. A buffer ETF holds FLEX options on its reference index rather than shares, so there is no holdings overlap between two of them to report.
Performance, window by window
| Total return | Gap to the reference | |||
|---|---|---|---|---|
| Window | CPST | SIXO | CPST | SIXO |
| 3 months | +1.0% | +2.1% | −1.5 pts | −0.4 pts |
| 6 months | +3.9% | +8.1% | −13.0 pts | −8.9 pts |
| 1 year | +5.2% | +8.1% | −10.5 pts | −7.7 pts |
| 3 years | not published | +34.5% | not published | −50.5 pts |
CPST and SIXO over each window. Every figure is an ETFIQ calculation with distributions reinvested. Source: ETFIQ. Open the live comparison on ETFIQ →
On the same fields
CPST and SIXO on the same fields, as of Oct 1, 2026. Source: ETFIQ.
CPST in plain words
The fund's price can fall 0.1% from here before the buffer starts absorbing losses, by the issuer's figure. In index terms, SPY can fall 0.1% from today's level to the point where the buffer begins. Protection left, in index points: 100.0% of the 100.0% buffer still sits below today's SPY level. 335 days remained on Oct 1, 2026. On Sep 1, 2027 the period ends and a new cap is set.
SIXO in plain words
From its price on Oct 1, 2026, the fund can gain about 7.3% more before it reaches its cap. The fund's price can fall 0.4% from here before the buffer starts absorbing losses, by the issuer's figure. In index terms, SPY can fall 0.0% from today's level to the point where the buffer begins. Protection left, in index points: 10.0% of the 10.0% buffer still sits below today's SPY level. 182 days remained on Oct 1, 2026. On Mar 31, 2027 the period ends and a new cap is set.
Questions people ask
ETFIQ links to the documents behind every figure. It is not affiliated with any issuer, and a link is not an endorsement. A comparison is not a recommendation.
ETFIQ, CPST against SIXO, data as of Oct 1, 2026. https://etfiq.com/compare/buffer/cpst-vs-sixo
Free to use with attribution. Every figure is calculated from a named public source; the method is at etfiq.com/methodology.
Cite this page. ETFIQ, CPST against SIXO, data as of Oct 1, 2026. https://etfiq.com/compare/buffer/cpst-vs-sixo Free to use with attribution; the underlying files are at Open data.
Other forms
- Plain
- ETFIQ, CPST against SIXO, data as of Oct 1, 2026. https://etfiq.com/compare/buffer/cpst-vs-sixo
- APA
- ETFIQ. (Oct 1, 2026). CPST against SIXO. Retrieved from https://etfiq.com/compare/buffer/cpst-vs-sixo
- Markdown
- [CPST against SIXO (ETFIQ, Oct 1, 2026)](https://etfiq.com/compare/buffer/cpst-vs-sixo)