index · S&P Dow Jones

SPX · S&P 500 Index

Equity index. Confirm the index provider and the venue's out-of-hours method before comparing two SPX-labelled contracts.

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Snapshot session: after-hours transitionNo scenario earnings date

Demonstration · Snapshot 25 Sep 2026, 20:00 UTC · Not a live feed, venue quotation, or verified term.

Cross-venue dispersion · Screen this name · Calendar

Reference anchor

5,728.00 pts

EPIC aggregate mark

5,732.95 pts

Equal-weight of venue marks. Not a tradable price.

Aggregate basis

0.09%

Median funding

0.0038%

Tracked 24h notional

522.47m USD

Tracked open interest

250.48m USD

Active venues in the book

Reference confidence

70Tradable reference, moderate caution

Illustrative path

Pinned to the snapshot. Not a historical tape. Session shading is described on AfterClose rather than drawn as a false time axis.

Venue comparison

Venue	Symbol	Mark	Reference	Basis	Funding	Next funding	Interval	Leverage	Collateral	Settlement	Spread	Volume	Open interest	Confidence	Policy	Verified
Northline	NL-SPX-PERP	5,730.76 pts	5,728.00 pts	0.05%	0.0028%Longs pay shorts	26 Sep 2026 00:00 UTC	8h	20×	USDC	USDC	4.5 bps	320.19m	159.81m	70Tradable reference, moderate caution	Disclosed	Unverified
Aperture	A.SPX	5,735.13 pts	5,728.00 pts	0.12%	0.0038%Longs pay shorts	26 Sep 2026 00:00 UTC	4h	5×	USD	USD	6.4 bps	202.28m	90.68m	—Insufficient data	Disclosed	Unverified

Funding

Northline0.0028%Longs pay shorts
Aperture0.0038%Longs pay shorts

Basis

A basis gap is not automatically an arbitrage. Fees, funding, spread, slippage, collateral and access still apply.

Northline0.05%
Aperture0.12%

Liquidity

Northline

Spread 4.5 bps · depth 10 bps 1.04m · 25 bps 3.33m

Volume / open interest 2.00. Illustrative book, not a live ladder.

Aperture

Spread 6.4 bps · depth 10 bps 366.42k · 25 bps 2.33m

Volume / open interest 2.23. Illustrative book, not a live ladder.

Specification differences

Northline calls the mark “fair price” and the interval “eight-hour funding window”. Normalised: mark price, 8h funding, isolated or cross margin.
Aperture calls the mark “reference mark” and the interval “4-hour cycle”. Normalised: mark price, 4h funding, cross margin.

After the cash close

The snapshot was taken at 20:00 UTC on 25 Sep 2026, the US cash close. Marks in the book are not updated when the live session clock changes.

Open AfterClose

Risk disclosure status

Northline

1 categories not disclosed in the sample file. None of these venues is labelled safe.

Venue profile

Aperture

1 categories not disclosed in the sample file. None of these venues is labelled safe.

Venue profile

Corporate-action scenarios

No scenario is loaded for this name.

Eligibility

EPIC does not determine legal eligibility. Open the explorer for the sample access phrases.

Eligibility explorer

Why the median score is 70

Component contributions use the weights shown. This is anchor quality, not a valuation.

Primary cash-market status20%22
Reference-source freshness15%85
Independent source count10%64
Order-book depth10%92
Spread quality10%90
Mark versus last trade10%86
Related-instrument agreement10%75
Volatility regime5%75
Event-risk flag5%86
Price-band or stale-index condition5%85

The breakdown above is the first venue in the table, not a blended score.

Sources

Source type: EPIC demonstration dataset. Captured with the snapshot. Not an official API.

Score methodology

How to read a contract specification