{"schemaVersion":1,"asset":"BTC","reportDate":"2026-09-24","timestamps":{"currentSnapshotAt":"2026-09-24T16:30:00+00:00","previousSnapshotAt":"2026-09-23T16:30:00+00:00","generatedAt":"2026-09-24T16:30:39+00:00"},"comparison":{"status":"available","note":null},"provenance":{"reportArtifact":"published daily report","sourceReport":"BTC","sourceReportHref":"/reports/2026-09-24","source":"Derivasys proprietary historical SVI surface database","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":null},"tenors":[{"tenor":"1W","targetExpiry":1790872200361,"availability":"available","unavailableReason":null,"atmIv":{"current":31.7,"previous":33.8,"change":-2.1,"percentChange":-6.21},"rr25":{"current":-2.6,"previous":-1.74,"change":-0.86,"percentChange":-49.43},"bf25":{"current":1.96,"previous":2.26,"change":-0.3,"percentChange":-13.27}},{"tenor":"2W","targetExpiry":1791477000361,"availability":"available","unavailableReason":null,"atmIv":{"current":32.91,"previous":34.27,"change":-1.36,"percentChange":-3.97},"rr25":{"current":-1.69,"previous":-1.49,"change":-0.2,"percentChange":-13.42},"bf25":{"current":1.79,"previous":2.01,"change":-0.22,"percentChange":-10.95}},{"tenor":"1M","targetExpiry":1792859400361,"availability":"available","unavailableReason":null,"atmIv":{"current":34.4,"previous":34.9,"change":-0.5,"percentChange":-1.43},"rr25":{"current":-1.37,"previous":-1.52,"change":0.15,"percentChange":9.87},"bf25":{"current":1.77,"previous":1.96,"change":-0.19,"percentChange":-9.69}},{"tenor":"3M","targetExpiry":1798129800361,"availability":"available","unavailableReason":null,"atmIv":{"current":37.51,"previous":37.74,"change":-0.23,"percentChange":-0.61},"rr25":{"current":-0.94,"previous":-1.21,"change":0.27,"percentChange":22.31},"bf25":{"current":2,"previous":2.19,"change":-0.19,"percentChange":-8.68}},{"tenor":"6M","targetExpiry":1805992200361,"availability":"available","unavailableReason":null,"atmIv":{"current":38.5,"previous":39.01,"change":-0.51,"percentChange":-1.31},"rr25":{"current":-0.34,"previous":-0.46,"change":0.12,"percentChange":26.09},"bf25":{"current":2.22,"previous":2.32,"change":-0.1,"percentChange":-4.31}},{"tenor":"9M","targetExpiry":1813854600361,"availability":"available","unavailableReason":null,"atmIv":{"current":39.17,"previous":39.63,"change":-0.46,"percentChange":-1.16},"rr25":{"current":-0.13,"previous":-0.32,"change":0.19,"percentChange":59.38},"bf25":{"current":2.27,"previous":2.38,"change":-0.11,"percentChange":-4.62}},{"tenor":"1Y","targetExpiry":1821803400361,"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":null,"realisedVolatilityUnavailableReason":"Canonical BTC index coverage for 7d is incomplete: expected 10080 one-minute returns, found 9824 (97.4603% coverage); returns spanning missing minutes are excluded"}