CryptoTimes India USDC Premium Index · daily fix 11:30–12:30 IST · CTPI-USDC-SPOT-INR

As deployed: methodology v0.3.0 · generated automatically from the running index engine

Methodology v0.3.0 · effective 2026-07-30. Prior versions: see the changelog.

The daily fix is computed from order-book snapshots captured in the 11:30–12:30 IST window. Each constituent venue’s price is the median of its mid-quotes in the window, weighted by the median two-sided INR depth resting within ±100bps of mid. The index value is the depth-weighted median across eligible venues — moving it requires real resting depth, not printed prices. With two constituents, a depth-weighted median resolves to the deeper book’s price; on most days that is Coinbase. The sister index CTPI-USDT uses an unweighted median across a wider venue set; CTPI-USDC weights by depth because a two-venue universe makes an unweighted median vulnerable to a single thin book.

Constituents. Coinbase (INR order books) and KoinBX. Giottus is collected but excluded while its USDC book is inactive. Constituents are reviewed against the eligibility rules below; changes are versioned in the changelog.

Eligibility per window. An uncrossed book with at least ₹20,000 of two-sided depth within the band and at least 2 snapshots. The ₹20,000 floor is sized to current India-facing USDC book depth and will be revisited as venues grow. A snapshot minimum is used instead of a coverage floor because, with two venues, a coverage floor would routinely reduce the fix to a single book; depth weighting bounds the influence of thin participation instead. Venues failing structural quality review — for example, a book that does not update — are excluded at constituent level and disclosed.

References. The raw premium compares the fix to the ECB-derived USD/INR cross (EUR/INR ÷ EUR/USD, previous ECB business day). Around ECB holidays the most recent rate is carried for up to 5 calendar days; beyond that no daily fix is published for the day (fx_missing). The peg-adjusted premium additionally divides out the global USDC/USD rate (Kraken spot, single-sourced for its consistently deep USDC/USD book); if it is unavailable in-window, the fix publishes the raw premium with a data-quality flag and omits the peg-adjusted figure.

Weekends and holidays. No daily fix is published; an indicative reading is computed at the same time against the last ECB business day’s USD/INR, labelled with that rate’s date, marked indicative in the series and downloads, shown as a gold point on the chart, and never counted in the daily fix statistics.

Publication and failure. Daily fixes require two or more eligible venues and publishable references and are immutable once written. If fewer than two venues pass eligibility, no fix is published for that day — the gap stays visible in the series and the cause is recorded in the engine’s run log. Venue price disagreement above 150bps is disclosed on the fix as high venue dispersion, never hidden.

Restatement. A restatement is dry-run reviewed before being applied and recorded permanently in the corrections log with the original value, the corrected value, the reason, and both timestamps; restated fixes are annotated in the corrections log alongside the series.

Statistics. Rolling range statistics use 30 calendar days of the published series and include the marked pilot period (27–29 Jul); pilot fixes were computed under pre-release parameters, are flagged in every download, and are included so the statistic reflects the full published record.

As deployed: methodology v0.3.0 · generated automatically from the running index engine

2026-07-30 · methodology v0.3.0 — Fix window aligned to the family standard shared with CTPI-USDT: 11:30–12:30 IST. The pilot fixes of 27–29 Jul were computed under pre-release parameter sets (12:30–12:40 window) and are marked pilot in the series and downloads.
2026-07-29 · methodology v0.2.0 — Depth band set to ±100bps (a ±50bps band under-measured wide-spread books); per-instrument depth floors calibrated during the pilot period, to be re-reviewed at 30 days; venue dispersion disclosure added. Constituent review: KoinBX retained despite persistent positive deviation — its USDC/INR quotes reflect genuine retail-accessible prices for that instrument (its USDT book is assessed separately under CTPI-USDT), its influence is bounded by depth weighting, and dispersion is disclosed on every fix.
2026-07-27 · methodology v0.1.0 — Series begins. Collection live across three India-facing venues; one venue’s USDC book excluded for inactivity.

As deployed: methodology v0.3.0 · generated automatically from the running index engine

No corrections to date. Daily fixes are immutable once written; if a restatement is ever required it follows the restatement rule in the methodology — dry-run reviewed, then applied, then recorded here permanently with the original value, the corrected value, the reason, and both timestamps. An empty log is a good log.