Bitcoin options turn call-rich after sharp two-week skew shift
Bitcoin two-week RR25 rose 2.89 volatility points to 1.99 volatility points, moving call-side volatility above put-side volatility in a large 96.2 percentile move. The adjustment coincided with a 5.75-point rise in one-week ATM IV, while the 1Y-minus-1W ATM slope became less steep.
Prior comparison unavailable: the published 2026-09-02 edition is verified but ends at 2 Sept, 16:30 UTC; this window requires 2 Sept, 16:38 UTC.
A structured watchlist was not recorded or could not be verified in the prior edition; prior-watch outcomes remain unavailable.
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 ≥ 37.02 percent at . Current level 37.02; threshold is the current observed endpoint.
Full retrace: BTC 1W ATM IV ≤ 31.27 percent at . Current level 37.02; 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 2026-09-03T16:38:00+00:00 to 2026-09-04T16:38:00+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 2026-09-03T16:38:00+00:00 to 2026-09-04T16:38:00+00:00.
02 · Options market read
What the volatility surface did.
6 of 6 headline tenors were comparable at both endpoints. The largest ATM IV move was 1W at +5.75 volatility points, to 37.02%.
Derived directly from structured Derivasys surface data
03 · Catalyst check
02 Sept 2026, 16:38 UTC to 03 Sept 2026, 16:38 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 16:38 UTC cutoff, 1W ATM IV was 37.02%, 2.06 volatility points above seven-day realised volatility of 34.96%; 24-hour realised volatility was 38.38% and 30-day realised volatility was 36.91%.
Front end
Front-end ATM IV increased, averaging +4.20 volatility points to 37.40% across 1W, 2W and 1M.
Long end
Long-dated ATM IV increased, averaging +0.66 volatility points to 41.41% across 6M and 1Y.
Skew
RR25 moved towards calls, averaging +1.68 volatility points to 0.92 volatility points across the six available headline tenors.
Convexity
BF25 increased, averaging +0.11 volatility points to 2.50 volatility points across the six available headline tenors.
Largest standard-tenor move
The largest standard-tenor ATM IV move was +5.75 volatility points at 1W, to 37.02%.
Universe roll: added 7SEP26; removed 3SEP26. Comparisons use common expiries only.
RR25 moved towards calls, averaging +1.68 volatility points to 0.92 volatility points across the six available headline tenors. Negative RR25 denotes a richer 25-delta put wing under the call-minus-put convention.
BF25 increased, averaging +0.11 volatility points to 2.50 volatility points across the six 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
4SEP26, +29.36 vol pts1.6d
ATM IV change
5SEP26, +12.26 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
Expiry
Time left
Forward now (USD)
Forward change (USD)
ATM IV now
ATM IV change
RR25 change
BF25 change
4SEP26Expiry effect
0.6 days
80,838.84
+3431.76 USD
49.67%
+16.89 vol pts
+5.81 vol pts
+0.61 vol pts
5SEP26Expiry effect
1.6 days
80,870.12
+3451.36 USD
44.73%
+12.26 vol pts
+3.08 vol pts
+0.64 vol pts
6SEP26
2.6 days
80,877.25
+3450.12 USD
38.04%
+8.10 vol pts
+2.74 vol pts
+0.72 vol pts
11SEP26
7.6 days
80,908.21
+3459.35 USD
37.11%
+5.57 vol pts
+2.92 vol pts
+0.20 vol pts
18SEP26
14.6 days
80,963.03
+3467.47 USD
37.79%
+3.88 vol pts
+2.88 vol pts
+0.26 vol pts
25SEP26
21.6 days
81,004.16
+3493.60 USD
37.03%
+2.83 vol pts
+2.10 vol pts
+0.04 vol pts
30OCT26
56.6 days
81,384.54
+3494.35 USD
37.89%
+2.33 vol pts
+1.83 vol pts
+0.13 vol pts
27NOV26
84.6 days
81,707.09
+3518.90 USD
39.22%
+2.01 vol pts
+1.44 vol pts
-0.04 vol pts
25DEC26
112.6 days
82,009.49
+3511.45 USD
39.55%
+1.40 vol pts
+0.80 vol pts
+0.16 vol pts
26MAR27
203.6 days
82,930.62
+3521.22 USD
40.66%
+0.83 vol pts
+0.63 vol pts
+0.05 vol pts
25JUN27
294.6 days
83,941.9
+3541.92 USD
41.83%
+0.51 vol pts
+0.53 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.
4SEP26rotation towards calls · wing steepening5SEP26rotation towards calls · wing steepening6SEP26rotation towards calls · wing steepening11SEP26rotation towards calls · wing flattening18SEP26rotation towards calls25SEP26rotation towards calls · wing flattening30OCT26rotation towards calls27NOV26rotation towards calls25DEC26parallel shift higher · rotation towards calls26MAR27parallel shift higher25JUN27parallel shift higher
Surface movement heatmap
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
4SEP26
5SEP26
6SEP26
11SEP26
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 2.3 times VIX, while its 30-session return correlation with SPX was low at 0.11.
Implied-volatility premium
BTC 30-day ATM IV was 34.48%, against VIX at 15.20: a 19.28-point spread and 2.27× ratio.
Realised-volatility regime
BTC reported crypto realised volatility was 45.41%, versus SPX reported realised volatility of 7.59%. The spread ranked at percentile rank 78.8% of 226 prior observations.
Equity co-movement
Return correlation with SPX was 0.112 over 30 aligned sessions and 0.319 over 60 sessions. VIX9D, VIX and VIX3M closed at 12.57, 15.20 and 17.73.
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 02 Sept 2026, 20:00 UTC. Implied volatility and completed-session realised volatility use their respective observation windows shown above.
Evidence and methodology
Provider: yahoo_finance; quality: valid. Crypto RV annualised on sqrt(365); SPX RV on sqrt(252).
Evidence, source data and methodology
Report comparison baseline → current snapshot
2026-09-02 16:38:00 UTC → 2026-09-03 16:38:00 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 two-week RR25 rose 2.89 volatility points to 1.99 volatility points, moving call-side volatility above put-side volatility in a large 96.2 percentile move. The adjustment coincided with a 5.75-point rise in one-week ATM IV, while the 1Y-minus-1W ATM slope became less steep.
At report cutoff · Levels and stored endpoint changes
What matters now
Vol: BTC 1W ATM IV 37.02% · Δ +5.75 vol pts
Skew: BTC 1W RR25 1.94 vol pts · Δ +2.86 vol pts
Wings: BTC 1W BF25 2.16 vol pts · Δ +0.22 vol pts
Vol
BTC 1W ATM IV 37.02% · Δ +5.75 vol ptspercentile rank 93.2% by absolute move · full history (n=132)
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 27NOV26; the largest sigma change occurred at 30OCT26.
Expiry
Δ a
Δ b
Δ rho
Δ m
Δ sigma
Smile classification
4SEP26
0.00000
-0.00620
+0.22000
+0.07320
+0.03260
rotation towards calls, wing steepening
5SEP26
+0.00040
-0.00420
+0.04890
+0.00950
+0.01430
rotation towards calls, wing steepening
6SEP26
+0.00620
-0.00270
+0.06660
+0.01740
-0.04280
rotation towards calls, wing steepening
11SEP26
-0.00190
-0.00340
+0.03730
-0.00750
+0.02740
rotation towards calls, wing flattening
18SEP26
-0.00330
+0.00570
-0.01310
-0.04110
+0.00840
rotation towards calls
25SEP26
-0.00610
+0.00360
-0.00110
-0.03590
+0.03510
rotation towards calls, wing flattening
30OCT26
+0.03990
-0.02130
-0.15310
-0.09900
-0.12930
rotation towards calls
27NOV26
+0.02620
+0.01410
-0.21410
-0.17790
-0.09270
rotation towards calls
25DEC26
+0.00780
+0.00840
-0.03790
-0.04750
-0.03500
parallel shift higher, rotation towards calls
26MAR27
+0.00300
+0.00590
-0.04810
-0.07140
-0.00990
parallel shift higher
25JUN27
-0.04980
+0.03300
-0.08110
-0.12490
+0.07580
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 03 Sept 2026, 16:38:00 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 interpolated independently at 1W, 2W, 1M, 3M, 6M, 9M and 1Y; headline rankings prioritise 1W, 2W, 1M, 3M, 6M and 1Y.
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.
