01 · Executive summary
What changed across the BTC volatility surface.
Front-end ATM IV decreased, averaging -0.14 volatility points across 1W, 2W and 1M.
Long-dated ATM IV was broadly unchanged, averaging +0.07 volatility points across 6M and 1Y.
RR25 moved towards calls, averaging +0.28 volatility points across the six headline tenors.
BF25 decreased, averaging -0.13 volatility points across the six headline tenors.
The largest standard-tenor ATM IV move was -0.31 volatility points at 1W.
Universe roll: added 23MAY26; removed 19MAY26. Comparisons use common expiries only.
02 · Standard-tenor ranking
Largest surface events
Largest eligible smile rotation
22MAY26, -5.99 vol ptsLargest standard-tenor RR25 move
1M, +0.66 vol ptsLargest standard-tenor BF25 move
1W, -0.45 vol ptsLargest standard-tenor ATM IV move
1W, -0.31 vol ptsLargest eligible SVI sigma move
22MAY26, +0.2558 paramLargest eligible SVI rho move
22MAY26, -0.1913 param03 · ATM volatility
Standard-tenor ATM implied volatility.
| Tenor | Current (vol %) | Previous (vol %) | Change (vol pts) | Relative change |
|---|---|---|---|---|
| 1W | 36.44 | 36.75 | -0.31 vol pts | -0.84% |
| 2W | 36.59 | 36.74 | -0.15 vol pts | -0.41% |
| 1M | 37.32 | 37.29 | +0.03 vol pts | +0.08% |
| 3M | 39.16 | 39.01 | +0.15 vol pts | +0.38% |
| 6M | 42.11 | 42.06 | +0.05 vol pts | +0.12% |
| 9M | 43.63 | 43.57 | +0.06 vol pts | +0.14% |
| 1Y | 44.34 | 44.25 | +0.09 vol pts | +0.20% |
04 · Risk reversals
RR25 skew moved most at 1M.
RR25 moved towards calls, averaging +0.28 volatility points across the six headline tenors. Negative RR25 denotes a richer 25-delta put wing under the call-minus-put convention.
| Tenor | Current (vol %) | Previous (vol %) | Change (vol pts) |
|---|---|---|---|
| 1W | -4.62 | -5.05 | +0.43 vol pts |
| 2W | -6.13 | -6.41 | +0.28 vol pts |
| 1M | -6.07 | -6.73 | +0.66 vol pts |
| 3M | -5.89 | -6.01 | +0.12 vol pts |
| 6M | -5.37 | -5.60 | +0.23 vol pts |
| 9M | -4.96 | -5.09 | +0.13 vol pts |
| 1Y | -4.67 | -4.61 | -0.06 vol pts |
05 · Butterflies
BF25 convexity changed most at 1W.
BF25 decreased, averaging -0.13 volatility points across the six headline tenors. BF25 measures the average 25-delta wing premium over ATM IV.
| Tenor | Current (vol %) | Previous (vol %) | Change (vol pts) |
|---|---|---|---|
| 1W | 1.78 | 2.23 | -0.45 vol pts |
| 2W | 2.11 | 2.31 | -0.20 vol pts |
| 1M | 2.27 | 2.35 | -0.08 vol pts |
| 3M | 2.29 | 2.31 | -0.02 vol pts |
| 6M | 2.47 | 2.42 | +0.05 vol pts |
| 9M | 2.46 | 2.45 | +0.01 vol pts |
| 1Y | 2.37 | 2.47 | -0.10 vol pts |
06 · 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.
Smile rotation
21MAY26, -14.77 vol ptsATM IV change
20MAY26, -3.78 vol pts07 · Volatility term structure
Today against the previous 24-hour snapshot.
The ATM chart above is the standard-tenor term structure. The listed-expiry table below preserves the exchange maturity detail underneath those interpolated tenors.
| Expiry | Time left | Forward now (USD) | Forward change (USD) | ATM IV now | ATM IV change | RR25 change | BF25 change |
|---|---|---|---|---|---|---|---|
| 20MAY26Expiry effect | 0.3 days | 76,762.51 | -173.52 USD | 30.33% | -3.78 vol pts | +1.15 vol pts | -1.17 vol pts |
| 21MAY26Expiry effect | 1.3 days | 76,761.8 | -166.83 USD | 31.93% | -2.27 vol pts | -1.55 vol pts | -0.81 vol pts |
| 22MAY26 | 2.3 days | 76,766.45 | -179.00 USD | 34.66% | -1.00 vol pts | -0.44 vol pts | -0.76 vol pts |
| 29MAY26 | 9.3 days | 76,810.29 | -154.13 USD | 36.70% | -0.36 vol pts | +1.05 vol pts | -0.39 vol pts |
| 5JUN26 | 16.3 days | 76,834.62 | -151.28 USD | 36.56% | 0.00 vol pts | +0.21 vol pts | -0.19 vol pts |
| 26JUN26 | 37.3 days | 76,876.84 | -167.32 USD | 37.50% | -0.01 vol pts | +0.77 vol pts | -0.05 vol pts |
| 31JUL26 | 72.3 days | 77,025.97 | -145.55 USD | 38.41% | +0.23 vol pts | +0.15 vol pts | -0.07 vol pts |
| 25SEP26 | 128.3 days | 77,380.95 | -141.77 USD | 39.99% | -0.02 vol pts | +0.08 vol pts | +0.02 vol pts |
| 25DEC26 | 219.3 days | 78,081 | -156.20 USD | 42.94% | +0.03 vol pts | +0.29 vol pts | +0.09 vol pts |
| 26MAR27 | 310.3 days | 78,744.88 | -135.07 USD | 43.97% | +0.07 vol pts | +0.03 vol pts | -0.05 vol pts |
08 · 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.
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.
09 · SVI diagnostics
Daily movement in a, b, rho, m and sigma.
Among ranking-eligible expiries, the largest absolute rho change occurred at 22MAY26; the largest sigma change occurred at 22MAY26.
| Expiry | Δ a | Δ b | Δ rho | Δ m | Δ sigma | Smile classification |
|---|---|---|---|---|---|---|
| 20MAY26 | -0.01050 | -0.04030 | +0.00440 | -0.05190 | +0.61820 | parallel shift lower, rotation towards calls, wing steepening |
| 21MAY26 | +0.00650 | -0.02610 | -0.22990 | -0.10010 | +0.06830 | rotation towards puts, wing steepening |
| 22MAY26 | -0.03590 | +0.01640 | -0.19130 | -0.10960 | +0.25580 | rotation towards puts |
| 29MAY26 | -0.04610 | +0.02640 | -0.10860 | -0.05230 | +0.25000 | rotation towards calls |
| 5JUN26 | -0.02200 | +0.00830 | -0.10550 | -0.05810 | +0.11970 | rotation towards puts |
| 26JUN26 | -0.02930 | +0.01500 | -0.06250 | -0.03160 | +0.11850 | rotation towards calls |
| 31JUL26 | -0.03790 | +0.02200 | +0.00510 | +0.02400 | +0.12660 | parallel shift higher |
| 25SEP26 | +0.03150 | -0.01870 | -0.06310 | -0.06380 | -0.05100 | limited movement |
| 25DEC26 | +0.04600 | -0.01810 | -0.11420 | -0.14070 | -0.07420 | limited movement |
| 26MAR27 | +0.06050 | -0.03090 | -0.11310 | -0.12100 | -0.06420 | parallel shift higher |
10 · 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.
11 · Methodology and provenance
Generated from measured Derivasys surface data.
- Current snapshot
- 19 May 2026, 23:59 UTC
- Comparison snapshot
- 18 May 2026, 23:59 UTC
- Source
- 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
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