{"schemaVersion":1,"asset":"BTC","reportDate":"2026-09-26","timestamps":{"currentSnapshotAt":"2026-09-26T18:31:00+00:00","previousSnapshotAt":"2026-09-25T18:31:00+00:00","generatedAt":"2026-09-26T18:32:09+00:00"},"comparison":{"status":"available","note":null},"provenance":{"reportArtifact":"published daily report","sourceReport":"BTC","sourceReportHref":"/reports/2026-09-26","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":1791052260105,"availability":"available","unavailableReason":null,"atmIv":{"current":30.64,"previous":29.56,"change":1.08,"percentChange":3.65},"rr25":{"current":-1.12,"previous":-1.19,"change":0.07,"percentChange":5.88},"bf25":{"current":1.64,"previous":1.65,"change":-0.01,"percentChange":-0.61}},{"tenor":"2W","targetExpiry":1791657060105,"availability":"available","unavailableReason":null,"atmIv":{"current":31.94,"previous":31.72,"change":0.22,"percentChange":0.69},"rr25":{"current":-1.14,"previous":-1.16,"change":0.02,"percentChange":1.72},"bf25":{"current":1.64,"previous":1.6,"change":0.04,"percentChange":2.5}},{"tenor":"1M","targetExpiry":1793039460105,"availability":"available","unavailableReason":null,"atmIv":{"current":33.71,"previous":33.75,"change":-0.04,"percentChange":-0.12},"rr25":{"current":-1.03,"previous":-0.89,"change":-0.14,"percentChange":-15.73},"bf25":{"current":1.71,"previous":1.69,"change":0.02,"percentChange":1.18}},{"tenor":"3M","targetExpiry":1798309860105,"availability":"available","unavailableReason":null,"atmIv":{"current":37.09,"previous":37.22,"change":-0.13,"percentChange":-0.35},"rr25":{"current":-1.05,"previous":-0.72,"change":-0.33,"percentChange":-45.83},"bf25":{"current":2.07,"previous":2.04,"change":0.03,"percentChange":1.47}},{"tenor":"6M","targetExpiry":1806172260105,"availability":"available","unavailableReason":null,"atmIv":{"current":37.94,"previous":38.11,"change":-0.17,"percentChange":-0.45},"rr25":{"current":-0.59,"previous":-0.37,"change":-0.22,"percentChange":-59.46},"bf25":{"current":2.33,"previous":2.29,"change":0.04,"percentChange":1.75}},{"tenor":"9M","targetExpiry":1814034660105,"availability":"available","unavailableReason":null,"atmIv":{"current":38.74,"previous":38.87,"change":-0.13,"percentChange":-0.33},"rr25":{"current":-0.2,"previous":-0.1,"change":-0.1,"percentChange":-100},"bf25":{"current":2.44,"previous":2.4,"change":0.04,"percentChange":1.67}},{"tenor":"1Y","targetExpiry":1821983460105,"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":72,"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":"2026-09-26T18:31:00+00:00","spotWindowStart":"2026-09-25T18:31:00+00:00","spotMetric":"spot-index return","spotUnit":"percent","spotMove24hPercent":0.11,"rv24hPercent":15.57,"rv7dPercent":null,"rv30dPercent":null,"observations":{"24h":1440,"7d":10010,"30d":43130},"coverage":{"24h":{"status":"complete","observedReturns":1440,"expectedReturns":1440,"coveragePercent":100,"missingPriceMinutes":0,"missingIntervals":0,"largestMissingRunMinutes":0,"unavailableReason":null},"7d":{"status":"unavailable","observedReturns":10010,"expectedReturns":10080,"coveragePercent":99.3056,"missingPriceMinutes":68,"missingIntervals":2,"largestMissingRunMinutes":67,"unavailableReason":"7d RV requires at least 97% valid one-minute returns and no price gap over 60 minutes; coverage is 99.3056% with 68 missing price minutes across 2 intervals and a largest gap of 67 minutes."},"30d":{"status":"unavailable","observedReturns":43130,"expectedReturns":43200,"coveragePercent":99.838,"missingPriceMinutes":68,"missingIntervals":2,"largestMissingRunMinutes":67,"unavailableReason":"30d RV requires at least 99.5% valid one-minute returns and no price gap over 60 minutes; coverage is 99.8380% with 68 missing price minutes across 2 intervals and a largest gap of 67 minutes."}},"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":30.64,"oneWeekIvMinus7dRvPoints":null,"oneWeekIvMinus24hRvPoints":15.07,"oneWeekIvMinus30dRvPoints":null,"oneWeekIvTo7dRvRatio":null,"spreadPercentile":null},"realisedVolatilityUnavailableReason":null}