CPST vs DDTS: Cap, Buffer & Days Left

As of Oct 13, 2026 DDTS can fall 1.3% before its buffer engages and CPST 0.5%. Net assets on Oct 13, 2026: $41m for Calamos S&P 500 ® Structured Alt Protection ETF - September and $32m for Innovator Equity Dual Directional 10 Buffer ETF - Sep.

CPST costs 0.10 points a year less; their one-year returns differ by 5.8 points; CPST is 1.3 times larger.

Points (pts) are percentage points.

CPST vs DDTS: Cap, Buffer & Days Left
CPSTDDTS
Expense ratio0.69%0.79%
Net assets$41m$32m
Total return, 1 year+5.5%+11.3%
What it tracksSPYSPY
Holdings in commonnot published
Index fall to the buffer2.1%1.4%
CPSTFull floor
Full floorCPST: reference +2.1% since period start, fund +0.5%; buffer Floor; cap +8.1%; Full floor. Figures to Oct 13, 2026.full floor beneathfull floor0% period start+8.1% cap+2.1% gain captured+5.9% more to the capTODAY · SPY +2.1%Full floorCPST: reference +2.1% since period start, fund +0.5%; buffer Floor; cap +8.1%; Full floor. Figures to Oct 13, 2026.full floor beneathfull floor0% start+8.1% cap+2.1% gain captured+5.9% more to the capTODAY · SPY +2.1%

CPST: reference +2.1% since period start, fund +0.5%; buffer Floor; cap +8.1%; Full floor. Figures to Oct 13, 2026.

Figures to Oct 13, 2026.

DDTSBetween buffer and cap
Between buffer and capDDTS: reference +1.4% since period start, fund +1.2%; buffer 0 to −10; cap +14.7%; Between buffer and cap. Figures to Oct 13, 2026.10 pts of buffer+13.3% more to the cap−10.0% floor0% period start+14.7% cap+1.4% gain capturedTODAY · SPY +1.4%Between buffer and capDDTS: reference +1.4% since period start, fund +1.2%; buffer 0 to −10; cap +14.7%; Between buffer and cap. Figures to Oct 13, 2026.−10.0% floor0% start+14.7% cap10 pts of buffer+1.4% gain captured+13.3% more to the capTODAY · SPY +1.4%

DDTS: reference +1.4% since period start, fund +1.2%; buffer 0 to −10; cap +14.7%; Between buffer and cap. Figures to Oct 13, 2026.

DDTS: reference +1.4% since period start, fund +1.2%; buffer 0 to −10; cap +14.7%; Between buffer and cap. Figures to Oct 13, 2026.

These are two different products. CPST is a floor fund, which caps how far a holder can fall. DDTS 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 Aug 31, 2027, 322 days from now; DDTS runs to Aug 31, 2027, 322 days. A fall from here reaches CPST’s buffer after 0.5% and DDTS’s after 1.3%. Both track SPY, so what separates them is where each is in its own period.

Performance, window by window

Performance, window by window: CPST vs DDTS: Cap, Buffer & Days Left
Total returnGap to the reference's price return
WindowCPSTDDTSCPSTDDTS
3 months+1.2%+2.5%−2.3 pts−1.0 pts
6 months+3.2%+6.6%−8.8 pts−5.5 pts
1 year+5.5%+11.3%−11.8 pts−6.0 pts
Since launch
Not the same days: CPST Sep 2024 · DDTS Sep 2025
+14.1%+13.3%−26.9 pts−8.2 pts

Each fund's gap is to its reference's price return, dividends left out: the basis the outcome period uses. Source: ETFIQ. Open this comparison in the app →

On the same fields

CPST
Calamos S&P 500 ® Structured Alt Protection ETF - September · Absorbs the whole loss on SPY and caps the gain at 8.1%, over a period ending Aug 31, 2027
DDTS
Innovator Equity Dual Directional 10 Buffer ETF - Sep · Absorbs the first 10% of loss on SPY and caps the gain at 14.7%, over a period ending Aug 31, 2027
Reference index SPY SPY
Buffer 100% 10%
Outcome period Sep 1, 2026 to Aug 31, 2027 Aug 31, 2026 to Aug 31, 2027
Days left 322 322
Starting cap +8.1% +14.7%
Can still gain not published 13.2%
Fall before buffer 0.5% 1.3%
Protection left, index points 100.0% of 100.0% 10.0% of 10.0%
Index return this period +2.1% +1.4%
Fund return this period +0.5% +1.2%
State today Open Open
Expense ratio 0.69% 0.79%
Net assets $41m $32m

As of Oct 13, 2026. Source: ETFIQ.

About CPST

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 2.1% 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. 322 days remained on Oct 13, 2026. On Aug 31, 2027 the period ends and a new cap is set.

About DDTS

From its price on Oct 13, 2026, the fund can gain about 13.2% more before it reaches its cap. The fund's price can fall 1.3% from here before the buffer starts absorbing losses, by the issuer's figure. In index terms, SPY can fall 1.4% from today's level to the point where the buffer begins. Protection left, in index points: 10.0% of the 10.0% buffer still sits below today's SPY level.

Questions people ask

Which resets first, CPST or DDTS?
CPST ends its outcome period on Aug 31, 2027 and DDTS on Aug 31, 2027. A new cap is set the day after each.
Which is cheaper, CPST or DDTS?
CPST charges 0.69% a year and DDTS charges 0.79%, so CPST is cheaper. Fees come from each fund's prospectus.
Other comparisons
Where these figures came from

ETFIQ links to the documents behind every figure; a link is not an endorsement. A comparison is not a recommendation.

How this is computed

ETFIQ calculates every figure from each issuer’s published outcome-period terms. Buffer ETFs hold options on an index, not shares, so there is no holdings overlap to report.

Every figure is an ETFIQ calculation with distributions reinvested.

Cite this pageCitation, APA and Markdown

ETFIQ, CPST against DDTS, data as of Oct 13, 2026. https://etfiq.com/compare/buffer/cpst-vs-ddts

Open data

Free to use with attribution for figures ETFIQ computes; issuer data stays under its owner's terms.