CPST vs FSEP: which one stands where?
As of Oct 1, 2026 FSEP can fall 0.9% before its buffer engages and CPST 0.1%, and CPST resets 17 days sooner. Calamos S&P 500 ® Structured Alt Protection ETF - September and FT Vest U.S. Equity Buffer ETF - September.
CPST: reference +0.1% since period start, fund 0.0%; buffer −0 to floor; cap +8.0%; Full floor.
FSEP: reference +0.1% since period start, fund +0.1%; buffer 0 to −10; cap +16.7%; Between buffer and cap.
These are two different products. CPST is a floor fund, which caps how far a holder can fall. FSEP is a buffer fund, which absorbs the first part of a fall and leaves everything below it with the holder.
Where each one stands today
CPST resets first, on Sep 1, 2027, 335 days from now; FSEP runs to Sep 17, 2027, 352 days. A fall from here reaches CPST’s buffer after 0.1% and FSEP’s after 0.9%. 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 | FSEP | CPST | FSEP |
| 3 months | +1.0% | +3.7% | −1.5 pts | +1.2 pts |
| 6 months | +3.9% | +13.1% | −13.0 pts | −3.9 pts |
| 1 year | +5.2% | +13.0% | −10.5 pts | −2.7 pts |
| 3 years | not published | +54.1% | not published | −30.9 pts |
CPST and FSEP 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 FSEP 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.
FSEP in plain words
From its price on Oct 1, 2026, the fund can gain about 15.8% more before it reaches its cap. The fund's price can fall 0.9% from here before the buffer starts absorbing losses, by the issuer's figure. Protection left, in index points: 10.0% of the 10.0% buffer still sits below today's SPY level. 352 days remained on Oct 1, 2026. On Sep 17, 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 FSEP, data as of Oct 1, 2026. https://etfiq.com/compare/buffer/cpst-vs-fsep
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 FSEP, data as of Oct 1, 2026. https://etfiq.com/compare/buffer/cpst-vs-fsep Free to use with attribution; the underlying files are at Open data.
Other forms
- Plain
- ETFIQ, CPST against FSEP, data as of Oct 1, 2026. https://etfiq.com/compare/buffer/cpst-vs-fsep
- APA
- ETFIQ. (Oct 1, 2026). CPST against FSEP. Retrieved from https://etfiq.com/compare/buffer/cpst-vs-fsep
- Markdown
- [CPST against FSEP (ETFIQ, Oct 1, 2026)](https://etfiq.com/compare/buffer/cpst-vs-fsep)