CPST vs QBSF: which one stands where?
As of Oct 1, 2026 QBSF can fall 0.2% before its buffer engages and CPST 0.1%, and QBSF resets 243 days sooner. Calamos S&P 500 ® Structured Alt Protection ETF - September and AllianzIM U.S. Equity Buffer15 ETF - Jan.
CPST: reference +0.1% since period start, fund 0.0%; buffer −0 to floor; cap +8.0%; Full floor.
QBSF: reference 0.0% since period start, fund 0.0%; buffer 0 to −15; cap +2.9%; Between buffer and cap.
These are two different products. CPST is a floor fund, which caps how far a holder can fall. QBSF 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. QBSF has 92 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
QBSF resets first, on Dec 31, 2026, 92 days from now; CPST runs to Sep 1, 2027, 335 days. A fall from here reaches CPST’s buffer after 0.1% and QBSF’s after 0.2%. 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 | QBSF | CPST | QBSF |
| 3 months | +1.0% | +1.9% | −1.5 pts | −0.6 pts |
| 6 months | +3.9% | +4.8% | −13.0 pts | −12.2 pts |
| 1 year | +5.2% | +7.2% | −10.5 pts | −8.5 pts |
CPST and QBSF 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 QBSF 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.
QBSF in plain words
From its price on Oct 1, 2026, the fund can gain about 2.7% more before it reaches its cap. The fund's price can fall 0.2% 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: 15.0% of the 15.0% buffer still sits below today's SPY level. 92 days remained on Oct 1, 2026. On Dec 31, 2026 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 QBSF, data as of Oct 1, 2026. https://etfiq.com/compare/buffer/cpst-vs-qbsf
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 QBSF, data as of Oct 1, 2026. https://etfiq.com/compare/buffer/cpst-vs-qbsf Free to use with attribution; the underlying files are at Open data.
Other forms
- Plain
- ETFIQ, CPST against QBSF, data as of Oct 1, 2026. https://etfiq.com/compare/buffer/cpst-vs-qbsf
- APA
- ETFIQ. (Oct 1, 2026). CPST against QBSF. Retrieved from https://etfiq.com/compare/buffer/cpst-vs-qbsf
- Markdown
- [CPST against QBSF (ETFIQ, Oct 1, 2026)](https://etfiq.com/compare/buffer/cpst-vs-qbsf)