BTCSpot-index 24h +0.02%1W ATM IV 40.47%1W RR25 +0.78 vol pts1W BF25 +2.12 vol pts1W IV − 7D RV Unavailable
One-week BF25 increased while front-end ATM IV strengthened and call-side richness narrowed.
Previous report, watch levels and methodology
One-week surface context; the published headline retains its original evidence basis. Cutoffs 8 Sept, 16:30 UTC to 9 Sept, 16:30 UTC.
Previous publication · research context
2026-09-08: “Bitcoin options turn call-rich as front-end skew jumps”
Previous publication cutoff 8 Sept, 16:30 UTC. Today’s market comparison starts at 8 Sept, 16:30 UTC. Snapshot clocks align for the measured comparison below.
BTC 1W ATM IV: prior change +2.86 → current change +0.90 volatility points; same direction.
BTC 1W RR25: prior change +1.52 → current change -0.53 volatility points; direction reversed.
BTC 1W BF25: prior change +0.20 → current change +0.25 volatility points; same direction.
A structured watchlist was not recorded or could not be verified in the prior edition; this compares measured changes only.
Next daily cutoff: measurable checks
These checks are reconstructed from this edition’s stored endpoints; they were not recorded in the original report.
Hold the observed level: BTC 1W ATM IV ≥ 40.47 percent at . Current level 40.47; threshold is the current observed endpoint.
Full retrace: BTC 1W ATM IV ≤ 39.57 percent at . Current level 40.47; threshold is the previous observed endpoint.
Measurement basis and receipt
These are observed-level conditions for the next aligned cutoff, with no forecast or trade action. Spot uses exact index endpoints where available; ATM IV is quoted in percent and its change, RR25 and BF25 in volatility points. Derived from verified legacy artifact endpoints.
BTC:atmIv:1W:observed-current-level: rows[asset=BTC].report.tenors[tenor=1W].atmIv.previous; rows[asset=BTC].report.tenors[tenor=1W].atmIv.current; rows[asset=BTC].report.tenors[tenor=1W].atmIv.change; evaluation window 2026-09-09T16:30:00+00:00 to 2026-09-10T16:30:00+00:00.
BTC:atmIv:1W:observed-previous-level: rows[asset=BTC].report.tenors[tenor=1W].atmIv.previous; rows[asset=BTC].report.tenors[tenor=1W].atmIv.current; rows[asset=BTC].report.tenors[tenor=1W].atmIv.change; evaluation window 2026-09-09T16:30:00+00:00 to 2026-09-10T16:30:00+00:00.
Chart notes
Combined surface read: ATM IV rose (BTC); RR25 moved toward puts (BTC); BF25 wing premium increased (BTC).
02 · Options market read
What the volatility surface did.
5 of 6 headline tenors were comparable at both endpoints. The largest ATM IV move was 1W at +0.90 volatility points, to 40.47%.
Derived directly from structured Derivasys surface data
03 · Catalyst check
08 Sept 2026, 16:30 UTC to 09 Sept 2026, 16:30 UTC
News context unavailable.
News context unavailable because source coverage was incomplete.
04 · Detailed analysis
What changed across the BTC volatility surface.
Implied versus realised
At the 16:30 UTC cutoff, 1W ATM IV was 40.47%, 7.40 volatility points above seven-day realised volatility of 33.07%; 24-hour realised volatility was 37.01% and 30-day realised volatility was 38.42%.
Front end
Front-end ATM IV increased, averaging +0.69 volatility points to 39.36% across 1W, 2W and 1M.
Long end
Six-month ATM IV was broadly unchanged at 40.33% (+0.21 volatility points); 1Y was unavailable.
Skew
RR25 was broadly unchanged, averaging -0.08 volatility points to 0.34 volatility points across the five available headline tenors.
Convexity
BF25 increased, averaging +0.14 volatility points to 2.38 volatility points across the five available headline tenors.
Largest standard-tenor move
The largest standard-tenor ATM IV move was +0.90 volatility points at 1W, to 40.47%.
Universe roll: added 13SEP26; removed 9SEP26. Comparisons use common expiries only.
RR25 was broadly unchanged, averaging -0.08 volatility points to 0.34 volatility points across the five available headline tenors. Negative RR25 denotes a richer 25-delta put wing under the call-minus-put convention.
BF25 increased, averaging +0.14 volatility points to 2.38 volatility points across the five available headline tenors. BF25 measures the average 25-delta wing premium over ATM IV.
Contracts with fewer than 2 full days to expiry remain in the tables but are excluded from headline rankings. Settlement proximity, time decay, changing liquidity and fewer quotes can exaggerate their changes.
0.6d
Smile rotation
10SEP26, -7.30 vol pts1.6d
Smile rotation
11SEP26, -2.52 vol pts
10 · Volatility term structure
Today against the previous 24-hour snapshot.
Only fixed tenors bracketed by listed expiries at both snapshots are charted. The listed-expiry table preserves the observable exchange maturities underneath those interpolated points.
CurrentComparison snapshot
Suppressed outside the observable listed-expiry range: 1Y.
Expiry
Time left
Forward now (USD)
Forward change (USD)
ATM IV now
ATM IV change
RR25 change
BF25 change
10SEP26Expiry effect
0.6 days
78,602.74
-29.44 USD
34.52%
-1.67 vol pts
-1.83 vol pts
+0.39 vol pts
11SEP26Expiry effect
1.6 days
78,622.22
-20.81 USD
38.37%
+1.12 vol pts
-1.16 vol pts
+0.12 vol pts
12SEP26
2.6 days
78,631.38
-20.22 USD
43.02%
+2.97 vol pts
-0.04 vol pts
+0.52 vol pts
18SEP26
8.6 days
78,677.42
-8.21 USD
40.78%
+1.36 vol pts
-0.43 vol pts
+0.27 vol pts
25SEP26
15.6 days
78,734.23
+9.21 USD
38.95%
+0.78 vol pts
+0.11 vol pts
+0.15 vol pts
30OCT26
50.6 days
79,066.64
+15.26 USD
38.16%
+0.32 vol pts
-0.02 vol pts
-0.02 vol pts
27NOV26
78.6 days
79,369.87
+8.40 USD
39.40%
+0.14 vol pts
+0.17 vol pts
+0.17 vol pts
25DEC26
106.6 days
79,685.06
+12.98 USD
39.71%
+0.25 vol pts
+0.21 vol pts
+0.19 vol pts
26MAR27
197.6 days
80,624.8
+13.27 USD
40.40%
+0.20 vol pts
-0.03 vol pts
-0.03 vol pts
25JUN27
288.6 days
81,639.81
+24.53 USD
41.47%
+0.01 vol pts
-0.01 vol pts
+0.01 vol pts
11 · Smile movement
Reconstructed SVI smiles for every common expiry.
Each overlay uses the stored five-parameter SVI fit and the snapshot-specific time to expiry. Ultra-short expiries are displayed but do not determine the headline ranking.
Each cell is the fitted IV change in volatility points. Rows are listed expiries; columns run from the put wing through ATM to the call wing.
IV lowerIV higher
10SEP26
11SEP26
12SEP26
18SEP26
25SEP26
30OCT26
27NOV26
25DEC26
26MAR27
25JUN27
-0.30kATM+0.30k
Completed-session cross-asset context
Crypto volatility against US equity risk.
BTC 30-day implied volatility was 2.4 times VIX, while its 30-session return correlation with SPX was low at 0.19.
Implied-volatility premium
BTC 30-day ATM IV was 38.47%, against VIX at 15.72: a 22.75-point spread and 2.45× ratio.
Realised-volatility regime
BTC reported crypto realised volatility was 47.17%, versus SPX reported realised volatility of 8.54%. The spread ranked at percentile rank 81.2% of 229 prior observations.
Equity co-movement
Return correlation with SPX was 0.186 over 30 aligned sessions and 0.341 over 60 sessions. VIX9D, VIX and VIX3M closed at 14.81, 15.72 and 18.39.
RV comparison basis unverified: this edition does not record the recognised provider methodology for both horizons and annualisation conventions. The displayed spread rank does not establish matched-horizon comparability.
As of 08 Sept 2026, 20:00 UTC. Implied volatility and completed-session realised volatility use their respective observation windows shown above.
Evidence and methodology
market-context-v1; crypto RV annualized sqrt(365), SPX RV annualized sqrt(252); source provenance: DerivaSys canonical crypto index and Yahoo Finance ^GSPC/^VIX/^VIX9D/^VIX3M.
Evidence, source data and methodology
Report comparison baseline → current snapshot
2026-09-08 16:30:00 UTC → 2026-09-09 16:30:00 UTC
Changes use these stored market-snapshot baselines. The comparison baseline may differ from the snapshot used in the previous published edition.
Original report summary
Bitcoin one-week BF25 increased 0.25 volatility points to 2.12 volatility points, the day’s notable surface adjustment, while one-week ATM IV rose 0.90 points to 40.47%. The BF25 measure captures the relative richness of options away from the centre of the distribution. DerivaSys data showed front-end ATM IV averaging 39.36%, up 0.69 points; Bitcoin’s 24-hour spot-index return was 0.02%, and one-week implied volatility remained 7.40 points above seven-day realised volatility.
At report cutoff · Levels and stored endpoint changes
What matters now
Vol: BTC 1W ATM IV 40.47% · Δ +0.90 vol pts
Skew: BTC 1W RR25 0.78 vol pts · Δ -0.53 vol pts
Wings: BTC 1W BF25 2.12 vol pts · Δ +0.25 vol pts
Vol
BTC 1W ATM IV 40.47% · Δ +0.90 vol ptspercentile rank 31.2% by absolute move · full history (n=138)
Skew
BTC 1W RR25 0.78 vol pts · Δ -0.53 vol ptspercentile rank 37.7% by absolute move · full history (n=138)
These diagnostics preserve the fitted-surface audit trail without competing with the main market story.
Show SVI parameter changes and normalized Greeks
SVI diagnostics
Daily movement in a, b, rho, m and sigma.
Among ranking-eligible expiries, the largest absolute rho change occurred at 25JUN27; the largest sigma change occurred at 25DEC26.
Expiry
Δ a
Δ b
Δ rho
Δ m
Δ sigma
Smile classification
10SEP26
+0.01980
-0.01270
+0.01530
+0.01750
-0.19710
rotation towards puts, wing steepening
11SEP26
-0.00850
+0.01040
+0.09140
+0.05200
+0.02950
rotation towards puts, wing steepening
12SEP26
-0.01550
+0.02380
+0.05870
+0.03900
+0.01090
wing steepening
18SEP26
-0.03180
+0.03200
-0.01430
-0.01640
+0.08270
rotation towards puts, wing steepening
25SEP26
-0.03130
+0.03010
-0.03120
-0.03390
+0.08830
parallel shift higher, wing steepening
30OCT26
-0.02850
+0.02390
+0.02440
-0.01360
+0.09390
parallel shift higher
27NOV26
-0.01500
+0.00700
+0.05570
+0.02920
+0.03270
parallel shift higher
25DEC26
+0.05980
-0.02970
+0.00670
+0.05010
-0.14510
parallel shift higher
26MAR27
+0.04960
-0.03230
+0.02820
+0.04770
-0.07450
parallel shift higher
25JUN27
+0.03430
-0.02240
+0.08040
+0.09550
-0.04870
parallel shift higher
Current surface characteristics
Where normalized model Greek intensity is highest.
These are comparable Black-forward Greeks for a one-BTC ATM-forward call at each listed expiry—not portfolio exposure, open interest or a prediction of dealer positioning.
Thresholds are asset-specific policies recorded in this edition. Each window is assessed independently; returns spanning gaps are excluded. Partial estimates may miss volatility during gaps.
RV coverage and methodology
BTC · Unavailable · Surface cutoff 09 Sept 2026, 16:30:00 UTC · 7D coverage not recorded / not recorded required · largest 7D gap not recorded / not recorded maximum · maximum gap not recorded. RV suppressed — valid 7D coverage was not recorded. Full 7D coverage policy was not recorded.
Derivasys proprietary historical SVI surface and canonical BTC index databases
Realised volatility
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.
Comparison window
Nearest successful surface snapshots approximately 24 hours apart
RR convention
25-delta call IV minus 25-delta put IV
BF convention
Average 25-delta wing IV minus ATM forward IV
Fixed tenors
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.
Smile reconstruction
Listed-expiry smiles are reconstructed from stored SVI total-variance parameters on a fixed log-moneyness grid.
Ultra-short expiries
Expiries with fewer than 2 full days remaining stay in detailed tables but are excluded from headline rankings. Settlement proximity, time decay, changing liquidity and fewer quotes can exaggerate their changes.
Greek normalization
Black forward Greeks for a normalized one-BTC ATM-forward call, zero rate, fitted SVI IV
Catalyst policy
Only sufficiently relevant, reliably sourced events are shown; otherwise no catalyst is assigned.
