Coverage Inversion: Calibration-Transparent Fair-Value Oracles for Closed-Market Hours

Tokenized real-world assets trade continuously on public blockchains, but the
venues that price their underlyings do not. For roughly two-thirds of wall-clock
time, an on-chain protocol must value collateral against a market that is shut.

This record accompanies "Coverage Inversion: Calibration-Transparent Fair-Value
Oracles for Closed-Market Hours". The paper inverts the conventional
point-plus-confidence oracle interface: the target coverage level tau becomes a
published product input, and every served price band carries a calibration
receipt that a third party can reconstruct from public data.

CONTENTS

  The paper (67 pages) and the LaTeX source arXiv compiles.

  A reference implementation in three languages — the Python serving path, its
  Rust port (pinned to the Python by a 329-case parity harness), and the Anchor
  programs for the on-chain publish path.

  The calibration artefacts: the 20 deployment scalars that define the served
  bands, including the SHA-256-stamped frozen artefact used for out-of-sample
  validation.

  The public band archive: an append-only record of bands actually served, with
  Saturday width commitments published before Monday's open, so the claims can
  be audited after the fact rather than taken on trust.

EVIDENCE

  Two closed-market panels over the same ten US-listed tickers, 2014-2026:
  5,996 weekend windows (Friday close to Monday open) and 22,624 overnight
  windows (close to next open).

  The headline weekend result is held out by leave-one-symbol-out
  cross-validation at tau = 0.95: realised coverage 0.9497 +/- 0.0128, every
  fold passing Kupiec. On a 40-cell symbol-by-tau grid the architecture passes
  40 of 40 Kupiec tests, against 31 of 40 for the strongest practitioner
  baseline (GARCH-t).

  The same architecture, with only its gap selector changed, carries from
  weekends to overnight gaps — calibration transparency is a property of closed
  market hours generally, not of weekends specifically.

  Because an earnings release has a publicly known date and session, the band
  widens deterministically ahead of it. No incumbent oracle exposes
  calendar-conditioned coverage.

LICENSING

  This record is CC BY 4.0. The source code in the reference-implementation
  archive is Apache-2.0 and ships its own LICENSE file, which governs that
  archive.