Which resets first, CPST or OCTP?

CPST ends its outcome period on Sep 1, 2027 and OCTP on Sep 30, 2027. A new cap is set the day after each.

Which is cheaper, CPST or OCTP?

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

CPST vs OCTP: which one stands where?

As of Oct 1, 2026 OCTP can fall 0.5% before its buffer engages and CPST 0.1%, and CPST resets 30 days sooner. Calamos S&P 500 ® Structured Alt Protection ETF - September and PGIM S&P 500 Buffer 12 ETF - October.

CPSTFull floor

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

OCTPBetween buffer and cap

OCTP: reference 0.0% since period start, fund 0.0%; buffer 0 to −12; cap +16.3%; Between buffer and cap.

These are two different products. CPST is a floor fund, which caps how far a holder can fall. OCTP 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. CPST has 335 days of its period left and OCTP has 365, so the two are not the same bet on the same months.

Where each one stands today

CPST resets first, on Sep 1, 2027, 335 days from now; OCTP runs to Sep 30, 2027, 365 days. A fall from here reaches CPST’s buffer after 0.1% and OCTP’s after 0.5%. 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	OCTP	CPST	OCTP
3 months	+1.0%	+3.8%	−1.5 pts	+1.3 pts
6 months	+3.9%	+12.6%	−13.0 pts	−4.4 pts
1 year	+5.2%	+12.9%	−10.5 pts	−2.8 pts

CPST and OCTP 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

OCTP

PGIM S&P 500 Buffer 12 ETF - October · Absorbs the first 12% of loss on SPY and caps the gain at 16.3%, over a period ending Sep 30, 2027

Issuer Calamos PGIM

Reference index SPY SPY

Buffer 0% to 100% 12%

Outcome period Sep 1, 2026 to Sep 1, 2027 Oct 1, 2026 to Sep 30, 2027

Days left 335 365

Starting cap +8.0% +16.3%

Can still gain not published 15.8%

Fall before buffer 0.1% 0.5%

Protection left, index points 100.0% of 100.0% 12.0% of 12.0%

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 $32m

CPST and OCTP 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.

OCTP 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 0.5% 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: 12.0% of the 12.0% buffer still sits below today's SPY level. 365 days remained on Oct 1, 2026. On Sep 30, 2027 the period ends and a new cap is set.

Questions people ask

Which resets first, CPST or OCTP?: CPST ends its outcome period on Sep 1, 2027 and OCTP on Sep 30, 2027. A new cap is set the day after each.
Which is cheaper, CPST or OCTP?: CPST charges 0.69% a year and OCTP charges 0.50%, so OCTP is cheaper. Fees come from each fund's prospectus.

Other comparisons

CPST vs UOCT CPST vs USEP CPST vs XAUG CPST vs XBOC OCTP vs OCTT OCTP vs OCTU OCTP vs OCTW OCTP vs PBOC

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

Where these figures came from

CPST filings on SEC EDGAR ↗Calamos website ↗OCTP 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 OCTP, data as of Oct 1, 2026. https://etfiq.com/compare/buffer/cpst-vs-octp

Open data

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