The ETF universe is experiencing increasing complexity, with a notable surge in the popularity of options-based ETFs, particularly those focused on volatility selling. Over the past three years, the assets of US option-based ETFs have grown approximately 600% to $115 billion. SPY's average daily notional option trading volumes have tripled since 2021, reaching $409 billion this year. Additionally, actively managed ETF assets have grown by about 70% over the past year, reaching approximately $670 billion. The outstanding volume of US ETF options has risen to comfortably above $600 billion, making them the second-largest segment after index options.