ETH has been buoyed by favorable regulatory developments that appear to point growing possibilities of spot ether ETFs being authorised by the SEC after the regulator requested exchanges to replace 19b-4 filings, which suggest rule adjustments. In consequence, the ether implied volatility curve, which exhibits market expectations of future volatility throughout completely different strike costs and expirations, flattened as 25-delta threat reversals hit year-to-date highs above 18%, and merchants closely purchased $4,000 calls for twenty-four Could and 31 Could, Presto Analysis analysts wrote. A Polymarket contract asking if an ether ETF could be authorised by Could 31 jumped from 10 cents to 55 cents, representing a 55% likelihood that approval will happen by then.