The SPX order ledger

Every large order of a session, rebuilt from the tape as an ORDER rather than a print: the legs folded back into the parent, the structure named, and each one placed against the measured dealer book at the minute it printed.

Why a print feed gets this wrong

Most of what trades large in SPX is one leg of something. A feed that shows legs reports a “$4M call sweep” that was the short wing of a roll. How often that matters rises with size — measured over 684 sessions:

AboveOrders a dayAre structures
$100,00015058.2% [57.2, 59.1]
$250,0003870.1% [68.9, 71.4]
$500,0001576.3% [74.7, 77.9]

The interval is day-clustered: the unit is the SESSION, because one heavy expiry moves the share several points and two orders from the same day are not two independent observations.

Ranked by what it did to the book

Not by the size of the cheque. Those two orders agree 0.017 of the time, so eight of the ten biggest cheques of a day are not the ten that moved the book. Every rival ranks by money; this is the column they do not have, and it is the reason to read this one.

And about half the time we cannot tell you the side. A package signs or it does not, and when the rule cannot work out which way the customer went the row says so rather than printing a guess. That is the honest half of this product, and it is on this page rather than buried in the docs.

What is free

683 finished sessions (2024-01-02 to 2026-09-23) carry the ledger and are free to read, on the site and in the terminal. What a plan buys is TODAY — the session as it trades — and reading it from code.

See the plans · API and MCP

SPX only. An order is placed against the measured book, which is signed from the trade tape, and SPX is the only root that has one. Rebuilt from the public tape: not a trading signal and not investment advice.