6 of 6 headline tenors were comparable at both endpoints. The largest ATM IV move was 1W at -5.20 volatility points, to 31.93%.
Derived directly from structured Derivasys surface data
03 · Catalyst check
29 Jul 2026, 16:03 UTC to 30 Jul 2026, 16:03 UTC
Relevant context found; no confirmed catalyst
Relevant market events
2 events were retained after relevance scoring and event-level deduplication.
Confidencelow causal confidence
News is presented as contextual association unless the structured evidence supports a stronger relationship.
04 · Detailed analysis
What changed across the BTC volatility surface.
Front end
Front-end ATM IV decreased, averaging -3.80 volatility points to 32.61% across 1W, 2W and 1M.
Long end
Long-dated ATM IV decreased, averaging -0.21 volatility points to 41.30% across 6M and 1Y.
Skew
RR25 moved towards calls, averaging +0.80 volatility points to -3.88% across the six available headline tenors.
Convexity
BF25 decreased, averaging -0.22 volatility points to 2.26% across the six available headline tenors.
Largest standard-tenor move
The largest standard-tenor ATM IV move was -5.20 volatility points at 1W, to 31.93%.
Universe roll: added 21AUG26, 30OCT26, 3AUG26; removed 30JUL26. Comparisons use common expiries only.
05 · Standard-tenor ranking
Largest surface events
01
Largest eligible smile rotation
2AUG26, +8.26 vol pts02
Largest standard-tenor ATM IV move
1W, -5.20 vol pts03
Largest standard-tenor RR25 move
2W, +1.65 vol pts04
Largest standard-tenor BF25 move
1W, -0.40 vol pts05
Largest eligible SVI sigma move
2AUG26, +0.1758 param06
Largest eligible SVI rho move
26MAR27, -0.0481 param
06 · ATM volatility
Standard-tenor ATM implied volatility.
Tenor
Current (vol %)
Previous (vol %)
Change (vol pts)
Relative change
1W
31.93
37.13
-5.20 vol pts
-14.00%
2W
32.46
36.08
-3.62 vol pts
-10.03%
1M
33.44
36.01
-2.57 vol pts
-7.14%
3M
37.53
38.82
-1.29 vol pts
-3.32%
6M
40.31
40.60
-0.29 vol pts
-0.71%
9M
41.45
41.64
-0.19 vol pts
-0.46%
1Y
42.30
42.43
-0.13 vol pts
-0.31%
07 · Risk reversals
RR25 skew moved most at 2W.
RR25 moved towards calls, averaging +0.80 volatility points to -3.88% across the six available headline tenors. Negative RR25 denotes a richer 25-delta put wing under the call-minus-put convention.
CurrentPrevious day
Tenor
Current (vol %)
Previous (vol %)
Change (vol pts)
1W
-2.53
-4.09
+1.56 vol pts
2W
-3.31
-4.96
+1.65 vol pts
1M
-4.70
-5.46
+0.76 vol pts
3M
-4.72
-5.00
+0.28 vol pts
6M
-4.30
-4.61
+0.31 vol pts
9M
-4.08
-4.35
+0.27 vol pts
1Y
-3.70
-3.96
+0.26 vol pts
08 · Butterflies
BF25 convexity changed most at 1W.
BF25 decreased, averaging -0.22 volatility points to 2.26% across the six available headline tenors. BF25 measures the average 25-delta wing premium over ATM IV.
CurrentPrevious day
Tenor
Current (vol %)
Previous (vol %)
Change (vol pts)
1W
1.93
2.33
-0.40 vol pts
2W
1.93
2.22
-0.29 vol pts
1M
2.18
2.28
-0.10 vol pts
3M
2.30
2.66
-0.36 vol pts
6M
2.62
2.73
-0.11 vol pts
9M
2.64
2.71
-0.07 vol pts
1Y
2.58
2.64
-0.06 vol pts
09 · Expiry effects
Near-settlement moves, shown with context.
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.
0.7d
ATM IV change
31JUL26, -10.88 vol pts1.7d
ATM IV change
1AUG26, -10.80 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.
CurrentPrevious day
Expiry
Time left
Forward now (USD)
Forward change (USD)
ATM IV now
ATM IV change
RR25 change
BF25 change
31JUL26Expiry effect
0.7 days
64,698.75
+827.93 USD
32.89%
-10.88 vol pts
+3.12 vol pts
-1.80 vol pts
1AUG26Expiry effect
1.7 days
64,720.34
+842.38 USD
30.61%
-10.80 vol pts
+2.59 vol pts
-1.15 vol pts
2AUG26
2.7 days
64,728.82
+843.71 USD
26.59%
-9.90 vol pts
+2.83 vol pts
-1.21 vol pts
7AUG26
7.7 days
64,764.13
+847.92 USD
32.35%
-4.91 vol pts
+1.42 vol pts
-0.40 vol pts
14AUG26
14.7 days
64,814.88
+844.31 USD
32.47%
-3.40 vol pts
+1.78 vol pts
-0.28 vol pts
28AUG26
28.7 days
64,916.69
+848.39 USD
33.23%
-2.76 vol pts
+0.79 vol pts
-0.11 vol pts
25SEP26
56.7 days
65,120.31
+849.65 USD
35.46%
-1.47 vol pts
+0.51 vol pts
-0.11 vol pts
25DEC26
147.7 days
65,782.13
+890.12 USD
39.67%
-0.37 vol pts
+0.36 vol pts
-0.16 vol pts
26MAR27
238.7 days
66,447.95
+875.51 USD
40.95%
-0.25 vol pts
+0.27 vol pts
-0.05 vol pts
25JUN27
329.7 days
67,101.92
+854.23 USD
42.03%
-0.16 vol pts
+0.26 vol pts
-0.06 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.
31JUL26rotation towards calls · wing flattening1AUG26rotation towards calls · wing steepening2AUG26rotation towards calls · wing steepening7AUG26rotation towards calls · wing steepening14AUG26rotation towards calls · wing steepening28AUG26parallel shift lower · rotation towards calls · wing steepening25SEP26parallel shift lower25DEC26parallel shift lower26MAR27parallel shift lower25JUN27parallel shift lower
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
31JUL26
1AUG26
2AUG26
7AUG26
14AUG26
28AUG26
25SEP26
25DEC26
26MAR27
25JUN27
-0.30kATM+0.30k
12 · Technical appendix
Model parameters and normalized Greeks.
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 2AUG26.
Expiry
Δ a
Δ b
Δ rho
Δ m
Δ sigma
Smile classification
31JUL26
-0.03190
-0.04280
+0.06700
-0.03400
+0.67730
rotation towards calls, wing flattening
1AUG26
+0.01100
-0.03120
-0.02940
-0.04370
+0.07120
rotation towards calls, wing steepening
2AUG26
-0.00960
-0.01950
+0.01930
-0.02190
+0.17580
rotation towards calls, wing steepening
7AUG26
+0.00820
-0.01100
-0.00180
-0.01430
-0.02270
rotation towards calls, wing steepening
14AUG26
+0.00350
-0.00450
+0.03840
0.00000
-0.01090
rotation towards calls, wing steepening
28AUG26
+0.00900
-0.00670
+0.02520
-0.00630
-0.04460
parallel shift lower, rotation towards calls, wing steepening
25SEP26
-0.00520
+0.00210
-0.00310
-0.01470
+0.01230
parallel shift lower
25DEC26
-0.03160
+0.01700
-0.01560
-0.05710
+0.06880
parallel shift lower
26MAR27
+0.03660
-0.00820
-0.04810
-0.04360
-0.07130
parallel shift lower
25JUN27
+0.01050
-0.00890
+0.00170
-0.00360
-0.00970
parallel shift lower
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.
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.
