Bitcoin's recent price surge has sparked an "Uptober" rally, prompting 21 new cryptocurrency ETF filings as investors rush to gain exposure to the market through regulated products.Crypto ETFs let investors track digital asset prices without holding coins directly, and the current momentum has driven notable inflows from institutional and retail participants.Regulatory approval remains a key hurdle, but growing market interest and evolving frameworks suggest increased ETF adoption could follow if concerns around market integrity are addressed.