{"schemaVersion":1,"asset":"BTC","reportDate":"2026-07-21","timestamps":{"currentSnapshotAt":"2026-07-21T23:59:00+00:00","previousSnapshotAt":"2026-07-20T23:59:00+00:00","generatedAt":"2026-07-25T18:45:46+00:00"},"comparison":{"status":"available","note":null},"provenance":{"reportArtifact":"published daily report","sourceReport":"BTC","sourceReportHref":"/reports/2026-07-21","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 interpolated independently at 1W, 2W, 1M, 3M, 6M, 9M and 1Y; headline rankings prioritise 1W, 2W, 1M, 3M, 6M and 1Y.","realisedVolatility":null},"tenors":[{"tenor":"1W","targetExpiry":1785283141851,"availability":"available","unavailableReason":null,"atmIv":{"current":35.63,"previous":34.75,"change":0.88,"percentChange":2.53},"rr25":{"current":-0.16,"previous":-2.47,"change":2.31,"percentChange":93.52},"bf25":{"current":1.82,"previous":1.71,"change":0.11,"percentChange":6.43}},{"tenor":"2W","targetExpiry":1785887941851,"availability":"available","unavailableReason":null,"atmIv":{"current":35.49,"previous":34.63,"change":0.86,"percentChange":2.48},"rr25":{"current":-1.04,"previous":-3.18,"change":2.14,"percentChange":67.3},"bf25":{"current":2.06,"previous":1.88,"change":0.18,"percentChange":9.57}},{"tenor":"1M","targetExpiry":1787270341851,"availability":"available","unavailableReason":null,"atmIv":{"current":35.08,"previous":34.32,"change":0.76,"percentChange":2.21},"rr25":{"current":-2.43,"previous":-4.36,"change":1.93,"percentChange":44.27},"bf25":{"current":2.49,"previous":2.28,"change":0.21,"percentChange":9.21}},{"tenor":"3M","targetExpiry":1792540741851,"availability":"available","unavailableReason":null,"atmIv":{"current":37.91,"previous":37.58,"change":0.33,"percentChange":0.88},"rr25":{"current":-4.15,"previous":-5.36,"change":1.21,"percentChange":22.57},"bf25":{"current":2.77,"previous":2.68,"change":0.09,"percentChange":3.36}},{"tenor":"6M","targetExpiry":1800403141851,"availability":"available","unavailableReason":null,"atmIv":{"current":40.63,"previous":40.34,"change":0.29,"percentChange":0.72},"rr25":{"current":-4.57,"previous":-5.45,"change":0.88,"percentChange":16.15},"bf25":{"current":2.77,"previous":2.77,"change":0,"percentChange":0}},{"tenor":"9M","targetExpiry":1808265541851,"availability":"available","unavailableReason":null,"atmIv":{"current":41.73,"previous":41.54,"change":0.19,"percentChange":0.46},"rr25":{"current":-4.66,"previous":-5.27,"change":0.61,"percentChange":11.57},"bf25":{"current":2.68,"previous":2.71,"change":-0.03,"percentChange":-1.11}},{"tenor":"1Y","targetExpiry":1816214341851,"availability":"available","unavailableReason":null,"atmIv":{"current":42.55,"previous":42.52,"change":0.03,"percentChange":0.07},"rr25":{"current":-4.55,"previous":-4.98,"change":0.43,"percentChange":8.63},"bf25":{"current":2.55,"previous":2.56,"change":-0.01,"percentChange":-0.39}}],"realisedVolatility":null,"realisedVolatilityUnavailableReason":null}