# CPST (Calamos S&P 500 ® Structured Alt Protection ETF - September)

Calamos · Buffer ETFs · data as of Sep 12, 2026

As of Sep 12, 2026, CPST sits between its buffer and its cap, with SPY up 0.3% since the period began.

## Key facts

- CPST, fall before the buffer: 0.0%, as of Sep 12, 2026.
- CPST, protection left, index points: 100.0%, as of Sep 12, 2026.
- CPST, days to reset: 354, as of Sep 12, 2026.
- CPST, net assets: $32m (source, as filed for Apr 30, 2026).
- CPST, expense ratio: 0.69% (issuer page, Sep 12, 2026).
- CPST, reference index: SPY, as of Sep 12, 2026.

## Every published field

| Field | Value | Source |
| --- | --- | --- |
| Reference index | SPY | ETFIQ |
| Buffer | 100% | ETFIQ |
| Outcome period | Sep 1, 2026 to Sep 1, 2027 | ETFIQ |
| Starting cap | +8.0% | ETFIQ |
| SPY return since period start | +0.3% | ETFIQ |
| Fund return since period start | −0.1% | ETFIQ |
| Net assets | $32m | source, as filed for Apr 30, 2026 |
| Band state today | Open | ETFIQ |
| Can still gain | not published | issuer, fund price |
| Fall before buffer | 0.0% | issuer, fund price |
| Fall to the buffer in index terms | 0.3% | ETFIQ |
| Protection left in index points | 100.0% of 100.0% | ETFIQ |
| Days left in period | 354 | ETFIQ |
| Expense ratio | 0.69% | issuer page, Sep 12, 2026 |

## Questions

### How far can CPST fall before the buffer helps?

0.0% in fund-price terms on Sep 12, 2026, by the issuer's figure. In index terms SPY can fall 0.3% from that level before the buffer begins. Losses until that point are the holder's.

### How much of the CPST buffer is left?

100.0% of the 100.0% buffer sat below the SPY level on Sep 12, 2026. That is an ETFIQ calculation in index points, on one definition for every issuer.

### When does CPST reset?

The outcome period ends on Sep 1, 2027, 354 days from the data on Sep 12, 2026. A new cap is set the next day and the buffer starts again.

### What does CPST cost?

The prospectus expense ratio is 0.69% a year.


## Cite this page

ETFIQ, CPST, data as of Sep 12, 2026. https://etfiq.com/funds/CPST
Free to use with attribution; the underlying files are at https://etfiq.com/data/.

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