{"schemaVersion":1,"asset":"BTC","reportDate":"2026-09-28","timestamps":{"currentSnapshotAt":"2026-09-28T13:13:00+00:00","previousSnapshotAt":"2026-09-27T13:13:00+00:00","generatedAt":"2026-09-28T16:30:45+00:00"},"comparison":{"status":"available","note":null},"provenance":{"reportArtifact":"published daily report","sourceReport":"BTC","sourceReportHref":"/reports/2026-09-28","source":"Derivasys proprietary historical SVI surface and canonical BTC index databases","comparison":"Nearest successful surface snapshots approximately 24 hours apart","rrConvention":"25-delta call IV minus 25-delta put IV","bfConvention":"Average 25-delta wing IV minus ATM forward IV","fixedTenors":"Fixed-tenor measures are published only when listed expiries bracket the target at both comparison snapshots. Targets outside either observable range are suppressed, not extrapolated; headline rankings use only supported tenors.","realisedVolatility":"Annualised root-mean-square of one-minute canonical BTC-USD index log returns using a 365-day basis; all windows end at the current snapshot."},"tenors":[{"tenor":"1W","targetExpiry":1791205980899,"availability":"available","unavailableReason":null,"atmIv":{"current":34.6,"previous":31.82,"change":2.78,"percentChange":8.74},"rr25":{"current":-1.54,"previous":-0.48,"change":-1.06,"percentChange":-220.83},"bf25":{"current":1.74,"previous":1.82,"change":-0.08,"percentChange":-4.4}},{"tenor":"2W","targetExpiry":1791810780899,"availability":"available","unavailableReason":null,"atmIv":{"current":34.41,"previous":32.32,"change":2.09,"percentChange":6.47},"rr25":{"current":-1.44,"previous":-0.63,"change":-0.81,"percentChange":-128.57},"bf25":{"current":1.62,"previous":1.73,"change":-0.11,"percentChange":-6.36}},{"tenor":"1M","targetExpiry":1793193180899,"availability":"available","unavailableReason":null,"atmIv":{"current":35.15,"previous":33.68,"change":1.47,"percentChange":4.36},"rr25":{"current":-1.01,"previous":-0.8,"change":-0.21,"percentChange":-26.25},"bf25":{"current":1.75,"previous":1.9,"change":-0.15,"percentChange":-7.89}},{"tenor":"3M","targetExpiry":1798463580899,"availability":"available","unavailableReason":null,"atmIv":{"current":37.38,"previous":36.76,"change":0.62,"percentChange":1.69},"rr25":{"current":-0.72,"previous":-1.09,"change":0.37,"percentChange":33.94},"bf25":{"current":1.94,"previous":2.15,"change":-0.21,"percentChange":-9.77}},{"tenor":"6M","targetExpiry":1806325980899,"availability":"available","unavailableReason":null,"atmIv":{"current":38.11,"previous":37.75,"change":0.36,"percentChange":0.95},"rr25":{"current":-0.49,"previous":-0.71,"change":0.22,"percentChange":30.99},"bf25":{"current":2.05,"previous":2.35,"change":-0.3,"percentChange":-12.77}},{"tenor":"9M","targetExpiry":1814188380899,"availability":"available","unavailableReason":null,"atmIv":{"current":38.83,"previous":38.52,"change":0.31,"percentChange":0.8},"rr25":{"current":-0.17,"previous":-0.22,"change":0.05,"percentChange":22.73},"bf25":{"current":2.33,"previous":2.54,"change":-0.21,"percentChange":-8.27}},{"tenor":"1Y","targetExpiry":1822137180899,"availability":"unavailable","unavailableReason":"The target tenor falls outside the listed-expiry range at one or both snapshots; extrapolated values are suppressed.","atmIv":{"current":null,"previous":null,"change":null,"percentChange":null},"rr25":{"current":null,"previous":null,"change":null,"percentChange":null},"bf25":{"current":null,"previous":null,"change":null,"percentChange":null}}],"realisedVolatility":{"source":"canonical/BTC-USD-INDEX (DERIBIT and OKX indexes)","fallbackObservations":88,"fallbackPolicy":"Missing canonical minutes use the stored Deribit index first, then the stored OKX index; canonical bars always take precedence.","samplingInterval":"1 minute","annualizationBasis":"365 days","windowEnd":"2026-09-28T13:13:00+00:00","spotWindowStart":"2026-09-27T13:13:00+00:00","spotMetric":"spot-index return","spotUnit":"percent","spotMove24hPercent":-1.57,"rv24hPercent":31.12,"rv7dPercent":33.93,"rv30dPercent":34.73,"observations":{"24h":1440,"7d":10080,"30d":43200},"coverage":{"24h":{"status":"complete","observedReturns":1440,"expectedReturns":1440,"coveragePercent":100,"missingPriceMinutes":0,"missingIntervals":0,"largestMissingRunMinutes":0,"unavailableReason":null},"7d":{"status":"complete","observedReturns":10080,"expectedReturns":10080,"coveragePercent":100,"missingPriceMinutes":0,"missingIntervals":0,"largestMissingRunMinutes":0,"unavailableReason":null},"30d":{"status":"complete","observedReturns":43200,"expectedReturns":43200,"coveragePercent":100,"missingPriceMinutes":0,"missingIntervals":0,"largestMissingRunMinutes":0,"unavailableReason":null}},"coveragePolicy":{"version":"observed-minute-returns-v1","minimumCoveragePercent":null,"minimumCoveragePercentByWindow":{"24h":98,"7d":97,"30d":99.5},"maximumMissingRunMinutes":60,"methodology":"Each RV window qualifies independently. RV annualises the mean squared observed one-minute log return; returns spanning gaps are excluded, not interpolated or zero-filled. Partial estimates assume observed minutes are representative and may miss volatility during gaps."},"spotUnavailableReason":null,"oneWeekAtmIvPercent":34.6,"oneWeekIvMinus7dRvPoints":0.67,"oneWeekIvMinus24hRvPoints":3.48,"oneWeekIvMinus30dRvPoints":-0.13,"oneWeekIvTo7dRvRatio":null,"spreadPercentile":null},"realisedVolatilityUnavailableReason":null}