Which resets first, CPST or PQXX?

CPST ends its outcome period on Sep 1, 2027 and PQXX on Dec 31, 2026. A new cap is set the day after each.

Which is cheaper, CPST or PQXX?

CPST charges 0.69% a year and PQXX charges 0.50%, so PQXX is cheaper. Fees come from each fund's prospectus.

CPST vs PQXX: which one stands where?

As of Oct 1, 2026 PQXX can fall 0.1% before its buffer engages and CPST 0.1%, and PQXX resets 243 days sooner. Calamos S&P 500 ® Structured Alt Protection ETF - September and PGIM S&P 500 Quarterly Buffer 20 ETF.

CPSTFull floor

CPST: reference +0.1% since period start, fund 0.0%; buffer −0 to floor; cap +8.0%; Full floor.

PQXXBetween buffer and cap

PQXX: reference 0.0% since period start, fund 0.0%; buffer 0 to −20; cap +2.5%; Between buffer and cap.

These are two different products. CPST is a floor fund, which caps how far a holder can fall. PQXX 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. PQXX 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

PQXX 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 PQXX’s after 0.1%. 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	PQXX	CPST	PQXX
3 months	+1.0%	+2.4%	−1.5 pts	−0.1 pts
6 months	+3.9%	not published	−13.0 pts	not published
1 year	+5.2%	not published	−10.5 pts	not published

CPST and PQXX 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

Calamos S&P 500 ® Structured Alt Protection ETF - September · Absorbs losses from 0.0% to 100.0% on SPY and caps the gain at 8.0%, over a period ending Sep 1, 2027

PQXX

PGIM S&P 500 Quarterly Buffer 20 ETF · Absorbs the first 20% of loss on SPY and caps the gain at 2.5%, over a period ending Dec 31, 2026

Issuer Calamos PGIM

Reference index SPY SPY

Buffer 0% to 100% 20%

Outcome period Sep 1, 2026 to Sep 1, 2027 Oct 1, 2026 to Dec 31, 2026

Days left 335 92

Starting cap +8.0% +2.5%

Can still gain not published 2.4%

Fall before buffer 0.1% 0.1%

Protection left, index points 100.0% of 100.0% 20.0% of 20.0%

Index return this period +0.1% 0.0%

Fund return this period 0.0% 0.0%

State today Open Open

Expense ratio 0.69% 0.50%

Net assets $37m $3m

CPST and PQXX 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.

PQXX in plain words

From its price on Oct 1, 2026, the fund can gain about 2.4% more before it reaches its cap. In index terms, SPY can fall 0.0% from today's level to the point where the buffer begins. Protection left, in index points: 20.0% of the 20.0% 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

Which resets first, CPST or PQXX?: CPST ends its outcome period on Sep 1, 2027 and PQXX on Dec 31, 2026. A new cap is set the day after each.
Which is cheaper, CPST or PQXX?: CPST charges 0.69% a year and PQXX charges 0.50%, so PQXX is cheaper. Fees come from each fund's prospectus.

Other comparisons

CPST vs PQXV CPST vs QBSV CPST vs SEPM CPST vs SEPP PQXX vs GSEP PQXX vs JAJL PQXX vs JANP PQXX vs JANT

S&P 500 (SPY) →CPST on its own →PQXX on its own →How every figure is computed →Standards and sources →

Where these figures came from

CPST filings on SEC EDGAR ↗Calamos website ↗PQXX filings on SEC EDGAR ↗PGIM website ↗

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.

Cite this page

ETFIQ, CPST against PQXX, data as of Oct 1, 2026. https://etfiq.com/compare/buffer/cpst-vs-pqxx

Open data

Free to use with attribution. Every figure is calculated from a named public source; the method is at etfiq.com/methodology.