Data as of Sep 12, 2026. Both funds on the fields they both publish, from the same sources.
CPST vs SPLG: how they differ
CPST and SPLG are funds of different kinds, on the fields both publish.
Calamos S&P 500 ® Structured Alt Protection ETF - September and S&P 500, book from IVV.
| CPST Calamos S&P 500 ® Structured Alt Protection ETF - September | SPLG S&P 500, book from IVV | |
|---|---|---|
| Where it sits | Buffer ETF | Core index fund |
| Issuer | Calamos | S&P |
| What it is | Defined outcome, 100% on SPY | S&P 500, book from IVV |
| Total return, 1 year | not published | +17.6% |
| S&P 500 over the same days | not published | +17.5% |
| Gap to the S&P 500 | not available | +0.1 pts |
| Expense ratio | 0.69% | not published |
CPST in plain words
Protection left, in index points: 100.0% of the 100.0% buffer still sits below today's SPY level. 354 days remained on Sep 12, 2026. On Sep 1, 2027 the period ends and a new cap is set.
SPLG in plain words
SPLG is an index equity fund tracking the S&P 500. Over the year to Sep 11, 2026 it returned +17.6% with distributions reinvested, against +17.5% for the S&P 500 and +23.0% for the Nasdaq-100.
Questions people ask
- Are CPST and SPLG the same kind of fund?
- No. CPST is a buffer ETF and SPLG is an index ETF, so they are built for different jobs. The table compares what both publish: return, cost and what each actually holds.
Other comparisons
Where to next
Where these figures came from
ETFIQ links to the documents behind every figure. It is not affiliated with any issuer, and a link is not an endorsement.
Cite this page. ETFIQ, CPST against SPLG, data as of Sep 12, 2026. https://etfiq.com/compare/any/CPST-SPLG Free to use with attribution; the underlying files are at Open data.
A comparison is not a recommendation. Standards and sources