RR25 was broadly unchanged, averaging +0.02 volatility points to -3.61 volatility points across the six available headline tenors. Negative RR25 denotes a richer 25-delta put wing under the call-minus-put convention.
BF25 was broadly unchanged, averaging +0.01 volatility points to 2.09 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.
1.7d
Smile rotation
20AUG26, +3.58 vol pts0.7d
Smile rotation
19AUG26, -2.78 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
19AUG26Expiry effect
0.7 days
64,817.14
+719.82 USD
23.03%
+1.49 vol pts
+0.27 vol pts
-0.67 vol pts
20AUG26Expiry effect
1.7 days
64,830.89
+725.21 USD
23.83%
+0.92 vol pts
+1.02 vol pts
+0.14 vol pts
21AUG26
2.7 days
64,838.85
+724.81 USD
24.79%
-0.12 vol pts
+0.55 vol pts
-0.05 vol pts
28AUG26
9.7 days
64,893.15
+724.77 USD
27.81%
+0.15 vol pts
+0.65 vol pts
-0.15 vol pts
4SEP26
16.7 days
64,947.05
+722.89 USD
28.94%
-0.49 vol pts
+0.11 vol pts
+0.01 vol pts
25SEP26
37.7 days
65,112.57
+721.09 USD
33.57%
+0.22 vol pts
-0.12 vol pts
-0.02 vol pts
30OCT26
72.7 days
65,407.46
+721.17 USD
35.92%
+0.05 vol pts
-0.01 vol pts
+0.09 vol pts
25DEC26
128.7 days
65,861.62
+727.85 USD
38.75%
+0.24 vol pts
-0.22 vol pts
0.00 vol pts
26MAR27
219.7 days
66,557.8
+730.11 USD
40.16%
+0.39 vol pts
-0.03 vol pts
+0.01 vol pts
25JUN27
310.7 days
67,266.78
+725.50 USD
41.45%
+0.28 vol pts
-0.14 vol pts
+0.08 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.
19AUG26rotation towards puts · wing flattening20AUG26rotation towards calls · wing steepening21AUG26rotation towards calls · wing steepening28AUG26rotation towards calls4SEP26wing steepening25SEP26parallel shift higher30OCT26parallel shift higher25DEC26parallel shift higher26MAR27parallel 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
19AUG26
20AUG26
21AUG26
28AUG26
4SEP26
25SEP26
30OCT26
25DEC26
26MAR27
25JUN27
-0.30kATM+0.30k
Evidence, source data and methodology
Report comparison baseline → current snapshot
2026-08-17 16:05:00 UTC → 2026-08-18 16:05:00 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
ATM implied volatility increased across front and long maturities, led by the 6M tenor, while RR25 and BF25 remained broadly unchanged.
At report cutoff · Levels and stored endpoint changes
What matters now
Vol: BTC 1W ATM IV 27.28% · Δ +0.35 vol pts
Skew: BTC 1W RR25 -2.05 vol pts · Δ +0.46 vol pts
Wings: BTC 1W BF25 1.47 vol pts · Δ -0.12 vol pts
Vol
BTC 1W ATM IV 27.28% · Δ +0.35 vol ptspercentile rank 30.0% by absolute move · 30-day window (n=30)
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 26MAR27; the largest sigma change occurred at 4SEP26.
Expiry
Δ a
Δ b
Δ rho
Δ m
Δ sigma
Smile classification
19AUG26
-0.01420
-0.01330
-0.08320
-0.11130
+0.37810
rotation towards puts, wing flattening
20AUG26
+0.00520
-0.00610
+0.02830
+0.00620
-0.04760
rotation towards calls, wing steepening
21AUG26
-0.00200
+0.00170
-0.03780
-0.01710
+0.01610
rotation towards calls, wing steepening
28AUG26
-0.01560
+0.01340
+0.03040
+0.01300
+0.09830
rotation towards calls
4SEP26
-0.03310
+0.02960
-0.01910
-0.01290
+0.12180
wing steepening
25SEP26
-0.00910
+0.00390
+0.02040
+0.01020
+0.03470
parallel shift higher
30OCT26
+0.04640
-0.03920
+0.07480
+0.11580
-0.09520
parallel shift higher
25DEC26
+0.00720
-0.00690
+0.00350
+0.01570
-0.00710
parallel shift higher
26MAR27
+0.02900
-0.04270
+0.07500
+0.12230
-0.01070
parallel shift higher
25JUN27
+0.03430
-0.02000
+0.01560
+0.06020
-0.05380
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 18 Aug 2026, 16:05:00 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 database
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.
