ETH leads uneven 1W ATM volatility repricing

The reading

What the evidence says

The daily comparison shows uneven increases in ATM, or at-the-money, implied volatility. ETH 1W ATM IV changed by +3.27 vol points ^[1] to 55.62% ^[2], compared with BTC's +1.68 vol points ^[3] to 40.36% ^[4] and SOL's +0.84 vol points ^[5] to 57.02% ^[6]. The matched 1M comparison changes the ordering: SOL ATM IV changed by +1.71 vol points ^[7] to 56.10% ^[8], ETH by +1.12 vol points ^[9] to 53.55% ^[10], and BTC by +0.65 vol points ^[11] to 38.47% ^[12]. ETH and BTC therefore showed larger ATM increases at 1W than at 1M, while SOL showed the reverse. SOL's 1M absolute move ranked at 74.1st percentile ^[13] within its full captured eligible history, 54 observations (observed sampling; 09 Sep 2026–07 Nov 2026) ^[13]. That magnitude comparison does not establish an unusually rare cross-asset configuration.

RR25, the call-versus-put IV asymmetry, separates higher ATM volatility from directional protection pricing. BTC 1W RR25 changed by -1.01 vol points ^[14] to -4.44 vol points ^[15], while ETH 1W RR25 changed by -0.37 vol points ^[16] to -6.41 vol points ^[17]. These moves deepened existing downside biases. SOL instead showed 1W skew relief: RR25 changed by +0.69 vol points ^[18] to -3.39 vol points ^[19], remaining negative. The matched 1M evidence reverses the altcoin relationship: ETH RR25 changed by +0.74 vol points ^[20] to -3.32 vol points ^[21], easing its downside bias, whereas SOL changed by -0.35 vol points ^[22] to -1.70 vol points ^[23], deepening its downside bias. BTC 1M RR25 changed only by -0.09 vol points ^[24] to -3.63 vol points ^[25]. ETH and SOL thus had opposing skew adjustments across 1W and 1M; neither weekly result describes directional pricing across its entire surface.

Butterfly pricing provides a narrower supporting distinction. BF25 measures the average wing IV premium over ATM, rather than absolute wing IV or directional bias. At 1W, that premium changed by +0.04 vol points ^[26] for BTC, +0.16 vol points ^[27] for ETH and +0.24 vol points ^[28] for SOL. The 2W premiums stood at 1.14 vol points ^[29] for BTC, 1.91 vol points ^[30] for ETH and 1.59 vol points ^[31] for SOL, with respective changes of +0.01 vol points ^[32], -0.13 vol points ^[33] and +0.11 vol points ^[34]. At 1M, BTC BF25 changed by -0.01 vol points ^[35], ETH by -0.10 vol points ^[36], and SOL by +0.06 vol points ^[37] to 1.68 vol points ^[38]. SOL's butterfly premium therefore widened across these tenors, with the largest adjustment at 1W, even though its larger ATM increase occurred at 1M. ETH's butterfly premium narrowed at 2W and 1M despite widening at 1W. These modest butterfly changes support the tenor distinctions without establishing a separate broad wing repricing regime.

Spot and realized volatility qualify the interpretation of higher 1W ATM IV. Over the daily crypto comparison, spot changed by -0.17% ^[39] for BTC, -0.43% ^[40] for ETH and -0.78% ^[41] for SOL. Trailing realized volatility, recomputed from canonical minute prices over the common weekly horizon, was 38.37% ^[42], 49.46% ^[43] and 58.31% ^[44], respectively. Forward 1W IV minus trailing realized volatility was +1.99 vol points ^[45] for BTC, +6.16 vol points ^[46] for ETH and -1.29 vol points ^[47] for SOL. SOL combined the weakest spot return with 1W skew relief and a negative IV-minus-RV spread, underscoring why higher ATM IV should not be read as uniform defensive repricing. Separately, BTC's model-free DS30 reference was 43.71 vol points ^[48], versus BVIV at 42.63 vol points ^[49], leaving BVIV minus DS30 at -1.08 vol points ^[50]. Those independently timed references are distinct from fixed-tenor ATM IV. During the news window, ZeroHedge relayed Gulf attack and maritime incident reports. They provide a possible risk backdrop, but do not explain why ETH's ATM increase favored 1W while SOL's favored 1M.