5 of 6 headline tenors were comparable at both endpoints. The largest ATM IV move was 1W at +2.11 volatility points, to 48.21%.
Derived directly from structured Derivasys surface data
03 · Catalyst check
18 Sept 2026, 16:59 UTC to 19 Sept 2026, 16:59 UTC
No relevant catalyst identified.
No qualifying context was found in the monitored news sources for this reporting window.
04 · Detailed analysis
What changed across the ETH volatility surface.
Implied versus realised
At the 16:59 UTC cutoff, 1W ATM IV was 48.21%, 2.89 volatility points below seven-day realised volatility of 51.10%; 24-hour realised volatility was 44.14% and 30-day realised volatility was 53.44%.
Front end
Front-end ATM IV increased, averaging +0.98 volatility points to 48.13% across 1W, 2W and 1M.
Long end
Six-month ATM IV was broadly unchanged at 54.47% (0.00 volatility points); 1Y was unavailable.
Skew
RR25 moved towards calls, averaging +0.12 volatility points to 1.88% across the five available headline tenors.
Convexity
BF25 was broadly unchanged, averaging +0.05 volatility points to 3.05% across the five available headline tenors.
Largest standard-tenor move
The largest standard-tenor ATM IV move was +2.11 volatility points at 1W, to 48.21%.
Universe roll: added 23SEP26; removed 19SEP26. Comparisons use common expiries only.
05 · Standard-tenor ranking
Largest surface events
01
Largest eligible smile rotation
22SEP26, +5.04 vol pts02
Largest standard-tenor ATM IV move
1W, +2.11 vol pts03
Largest standard-tenor BF25 move
1W, +0.52 vol pts04
Largest standard-tenor RR25 move
1M, +0.42 vol pts05
Largest eligible SVI sigma move
25SEP26, -0.2376 param06
Largest eligible SVI rho move
30OCT26, -0.2132 param
06 · ATM volatility
Standard-tenor ATM implied volatility.
Tenor
Current (vol %)
Previous (vol %)
Change (vol pts)
Relative change
1W
48.21
46.10
+2.11 vol pts
+4.58%
2W
47.56
46.53
+1.03 vol pts
+2.21%
1M
48.61
48.80
-0.19 vol pts
-0.39%
3M
52.62
52.79
-0.17 vol pts
-0.32%
6M
54.47
54.47
0.00 vol pts
0.00%
9M
55.43
55.19
+0.24 vol pts
+0.43%
1Y
Unavailable
Unavailable
Unavailable
Unavailable
07 · Risk reversals
RR25 skew moved most at 1M.
RR25 moved towards calls, averaging +0.12 volatility points to 1.88% across the five 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
2.13
1.87
+0.26 vol pts
2W
2.53
2.54
-0.01 vol pts
1M
2.05
1.63
+0.42 vol pts
3M
1.09
1.34
-0.25 vol pts
6M
1.58
1.39
+0.19 vol pts
9M
1.59
1.53
+0.06 vol pts
1Y
Unavailable
Unavailable
Unavailable
08 · Butterflies
BF25 convexity changed most at 1W.
BF25 was broadly unchanged, averaging +0.05 volatility points to 3.05% across the five 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
2.85
2.33
+0.52 vol pts
2W
3.07
3.02
+0.05 vol pts
1M
2.95
2.93
+0.02 vol pts
3M
3.23
3.38
-0.15 vol pts
6M
3.16
3.37
-0.21 vol pts
9M
2.87
2.99
-0.12 vol pts
1Y
Unavailable
Unavailable
Unavailable
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.
0.6d
Smile rotation
20SEP26, +11.39 vol pts1.6d
Smile rotation
21SEP26, +6.83 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
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
20SEP26Expiry effect
0.6 days
2,649.64
+53.64 USD
33.71%
+1.24 vol pts
+1.20 vol pts
-0.42 vol pts
21SEP26Expiry effect
1.6 days
2,651.15
+54.69 USD
32.60%
-2.39 vol pts
+0.62 vol pts
-1.00 vol pts
22SEP26
2.6 days
2,651.24
+54.07 USD
41.05%
+1.04 vol pts
+1.52 vol pts
+0.62 vol pts
25SEP26
5.6 days
2,652.8
+54.21 USD
48.69%
+2.63 vol pts
+0.20 vol pts
+0.46 vol pts
2OCT26
12.6 days
2,654.94
+54.86 USD
47.33%
+0.85 vol pts
-0.16 vol pts
+0.08 vol pts
9OCT26
19.6 days
2,656.36
+54.68 USD
48.15%
+1.00 vol pts
+0.63 vol pts
+0.15 vol pts
30OCT26
40.6 days
2,660.98
+54.31 USD
48.83%
-0.95 vol pts
+0.38 vol pts
-0.06 vol pts
27NOV26
68.6 days
2,670.46
+54.34 USD
51.77%
-0.14 vol pts
+0.15 vol pts
+0.17 vol pts
25DEC26
96.6 days
2,680.33
+55.24 USD
52.77%
-0.21 vol pts
-0.31 vol pts
-0.23 vol pts
26MAR27
187.6 days
2,706.19
+55.43 USD
54.53%
0.00 vol pts
+0.21 vol pts
-0.21 vol pts
25JUN27
278.6 days
2,732.49
+55.74 USD
55.47%
+0.24 vol pts
+0.05 vol pts
-0.11 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.
20SEP26rotation towards calls · wing steepening21SEP26rotation towards calls · wing flattening22SEP26rotation towards calls · wing steepening25SEP26wing steepening2OCT26rotation towards puts · wing steepening9OCT26parallel shift higher · rotation towards calls30OCT26parallel shift lower27NOV26limited movement25DEC26parallel shift lower26MAR27limited movement25JUN27parallel 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
20SEP26
21SEP26
22SEP26
25SEP26
2OCT26
9OCT26
30OCT26
27NOV26
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 30OCT26; the largest sigma change occurred at 25SEP26.
Expiry
Δ a
Δ b
Δ rho
Δ m
Δ sigma
Smile classification
20SEP26
+0.03000
-0.04380
+0.03180
+0.01620
-0.00820
rotation towards calls, wing steepening
21SEP26
-0.03370
-0.02100
-0.07920
-0.05710
+0.39740
rotation towards calls, wing flattening
22SEP26
+0.05120
-0.03490
+0.01990
-0.00680
-0.23460
rotation towards calls, wing steepening
25SEP26
+0.06070
-0.02770
-0.05490
-0.01310
-0.23760
wing steepening
2OCT26
+0.03110
-0.01400
-0.15560
-0.08110
-0.11470
rotation towards puts, wing steepening
9OCT26
+0.02910
-0.00220
-0.20750
-0.13050
-0.12740
parallel shift higher, rotation towards calls
30OCT26
+0.02270
-0.00060
-0.21320
-0.14270
-0.10420
parallel shift lower
27NOV26
+0.01920
+0.00950
-0.20500
-0.13210
-0.11100
limited movement
25DEC26
+0.02790
-0.01660
-0.09450
-0.04970
-0.07270
parallel shift lower
26MAR27
+0.02450
-0.00270
-0.12440
-0.09270
-0.08440
limited movement
25JUN27
-0.05260
+0.06500
-0.10690
-0.16790
+0.05590
parallel shift higher
Current surface characteristics
Where normalized model Greek intensity is highest.
These are comparable Black-forward Greeks for a one-ETH ATM-forward call at each listed expiry—not portfolio exposure, open interest or a prediction of dealer positioning.
ETH 30-day implied volatility was 3.3 times VIX, while its 30-session return correlation with SPX was low at 0.20.
Implied-volatility premium
ETH 30-day ATM IV was 48.50%, against VIX at 14.81: a 33.69-point spread and 3.27× ratio.
Realised-volatility regime
ETH 20-calendar-day realised volatility was 50.63%, versus SPX 20-session realised volatility of 9.38%. The spread ranked at 37.2 percentile of 234 prior observations.
Equity co-movement
Return correlation with SPX was 0.196 over 30 aligned sessions and 0.231 over 60 sessions. VIX9D, VIX and VIX3M closed at 12.27, 14.81 and 18.24.
As of 18 Sept 2026, 20:00 UTC. Crypto RV uses sqrt(365); SPX RV uses sqrt(252).
13 · Methodology and provenance
Generated from measured Derivasys surface data.
Current snapshot
19 Sept 2026, 16:59 UTC
Comparison snapshot
18 Sept 2026, 16:59 UTC
Source
Derivasys proprietary historical SVI surface and canonical ETH index databases
Realised volatility
Annualised root-mean-square of one-minute canonical ETH-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-ETH ATM-forward call, zero rate, fitted SVI IV
Catalyst policy
Only sufficiently relevant, reliably sourced events are shown; otherwise no catalyst is assigned.
