BTC daily surface: 1W ATM IV falls 0.39 volatility points
Across the six available headline tenors, ATM IV averaged -0.14 volatility points, RR25 +0.06 volatility points and BF25 0.00 volatility points between the stored endpoints.
6 of 6 headline tenors were comparable at both endpoints. The largest ATM IV move was 1W at -0.39 volatility points, to 32.48%.
03 · Catalyst check
No catalyst assigned.
No qualifying context was identified after a healthy coverage check.
04 · Detailed analysis
What changed across the BTC volatility surface.
Front end
Front-end ATM IV decreased, averaging -0.25 volatility points to 33.44% across 1W, 2W and 1M.
Long end
Long-dated ATM IV was broadly unchanged, averaging -0.07 volatility points to 41.50% across 6M and 1Y.
Skew
RR25 was broadly unchanged, averaging +0.06 volatility points to -4.35% across the six available headline tenors.
Convexity
BF25 was unchanged at 2.26% across the six available headline tenors.
Largest standard-tenor move
The largest standard-tenor ATM IV move was -0.39 volatility points at 1W.
Universe roll: added 21JUL26; removed 17JUL26. Comparisons use common expiries only.
05 · Standard-tenor ranking
Largest surface events
01
Largest eligible smile rotation
20JUL26, -1.74 vol pts02
Largest standard-tenor ATM IV move
1W, -0.39 vol pts03
Largest standard-tenor RR25 move
1M, +0.38 vol pts04
Largest standard-tenor BF25 move
1W, +0.16 vol pts05
Largest eligible SVI rho move
31JUL26, -0.1141 param06
Largest eligible SVI sigma move
7AUG26, +0.0948 param
06 · ATM volatility
Standard-tenor ATM implied volatility.
Tenor
Current (vol %)
Previous (vol %)
Change (vol pts)
Relative change
1W
32.48
32.87
-0.39 vol pts
-1.19%
2W
33.72
33.81
-0.09 vol pts
-0.27%
1M
34.12
34.38
-0.26 vol pts
-0.76%
3M
37.60
37.57
+0.03 vol pts
+0.08%
6M
40.47
40.46
+0.01 vol pts
+0.02%
9M
41.65
41.69
-0.04 vol pts
-0.10%
1Y
42.53
42.67
-0.14 vol pts
-0.33%
07 · Risk reversals
RR25 skew moved most at 1M.
RR25 was broadly unchanged, averaging +0.06 volatility points to -4.35% 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
-1.93
-2.29
+0.36 vol pts
2W
-3.08
-3.03
-0.05 vol pts
1M
-4.50
-4.88
+0.38 vol pts
3M
-5.67
-5.71
+0.04 vol pts
6M
-5.73
-5.56
-0.17 vol pts
9M
-5.56
-5.33
-0.23 vol pts
1Y
-5.22
-5.00
-0.22 vol pts
08 · Butterflies
BF25 convexity changed most at 1W.
BF25 was unchanged at 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
1.59
1.43
+0.16 vol pts
2W
1.74
1.71
+0.03 vol pts
1M
2.16
2.24
-0.08 vol pts
3M
2.67
2.73
-0.06 vol pts
6M
2.75
2.82
-0.07 vol pts
9M
2.72
2.73
-0.01 vol pts
1Y
2.64
2.64
0.00 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.
0.3d
ATM IV change
18JUL26, -15.25 vol pts1.3d
ATM IV change
19JUL26, -12.03 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
18JUL26Expiry effect
0.3 days
63,901.41
+103.70 USD
17.36%
-15.25 vol pts
-1.98 vol pts
-0.66 vol pts
19JUL26Expiry effect
1.3 days
63,899.48
+88.49 USD
16.99%
-12.03 vol pts
-0.20 vol pts
-0.38 vol pts
20JUL26
2.3 days
63,914.33
+96.87 USD
23.80%
-6.00 vol pts
-0.14 vol pts
-0.04 vol pts
24JUL26
6.3 days
63,939.73
+109.58 USD
32.21%
-0.78 vol pts
+0.60 vol pts
+0.10 vol pts
31JUL26
13.3 days
63,964.41
+90.87 USD
33.68%
-0.15 vol pts
+0.14 vol pts
+0.02 vol pts
7AUG26
20.3 days
64,014.8
+79.91 USD
33.95%
-0.07 vol pts
+0.37 vol pts
-0.21 vol pts
28AUG26
41.3 days
64,174.77
+82.05 USD
34.22%
-0.41 vol pts
+0.44 vol pts
-0.04 vol pts
25SEP26
69.3 days
64,378.38
+81.50 USD
35.74%
-0.07 vol pts
+0.19 vol pts
-0.05 vol pts
25DEC26
160.3 days
65,002.07
+108.87 USD
40.03%
-0.01 vol pts
-0.14 vol pts
-0.08 vol pts
26MAR27
251.3 days
65,729.8
+125.89 USD
41.35%
-0.01 vol pts
-0.24 vol pts
-0.04 vol pts
25JUN27
342.3 days
66,436.62
+133.29 USD
42.36%
-0.13 vol pts
-0.23 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.
18JUL26rotation towards puts · wing steepening19JUL26rotation towards puts · wing steepening20JUL26rotation towards puts · wing steepening24JUL26rotation towards calls · wing steepening31JUL26wing steepening7AUG26rotation towards calls28AUG26rotation towards calls25SEP26limited movement25DEC26limited movement26MAR27limited movement25JUN27parallel 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
18JUL26
19JUL26
20JUL26
24JUL26
31JUL26
7AUG26
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 31JUL26; the largest sigma change occurred at 7AUG26.
Expiry
Δ a
Δ b
Δ rho
Δ m
Δ sigma
Smile classification
18JUL26
-0.05410
+0.02210
-0.01960
-0.04370
+0.37480
rotation towards puts, wing steepening
19JUL26
-0.02180
+0.02520
-0.04080
-0.03430
+0.07370
rotation towards puts, wing steepening
20JUL26
+0.00200
+0.00850
-0.06900
-0.04230
-0.06570
rotation towards puts, wing steepening
24JUL26
+0.00590
+0.00330
-0.07240
-0.06130
-0.05920
rotation towards calls, wing steepening
31JUL26
+0.00370
-0.00340
-0.11410
-0.08460
-0.01190
wing steepening
7AUG26
-0.02140
+0.00890
+0.03620
+0.02830
+0.09480
rotation towards calls
28AUG26
-0.01040
+0.01040
+0.04380
+0.01690
+0.02720
rotation towards calls
25SEP26
-0.02330
+0.01640
+0.04170
+0.01780
+0.05760
limited movement
25DEC26
-0.02530
+0.00170
+0.08750
+0.07700
+0.06040
limited movement
26MAR27
-0.03350
-0.00330
+0.08280
+0.08990
+0.07400
limited movement
25JUN27
-0.03440
-0.01960
+0.08820
+0.12110
+0.07990
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
