ETF does not usually hold "money", so it does not make sense to ask about "percentage". ETF does however hold stocks and the like. According to BlackRock, "ETFs

ETF does not usually hold "money", so it does not make sense to ask about "percentage". ETF does however hold stocks and the like. According to BlackRock, "ETFs represent 12.7% of equity assets in the U.S., 8.5% in Europe, and 4.4% in Asia-Pacific." [1] But I think the closest should be comparing to Gold ETF since Bitcoin now is more considered to be a commodity, or event "digital gold". It would be around 2% according to Wikipedia. [2] [1]: https://www.ishares.com/us/insights/global-etf-facts#:~:text=ETF%20MARKET%20SIZE&text=ETFs%20represent%2012.7%25%20of%20equity,4.4%25%20in%20Asia%2DPacific https://www.ishares.com/us/insights/global-etf-facts#:~:text.... [2]: https://en.wikipedia.org/wiki/Gold_holdings https://en.wikipedia.org/wiki/Gold_holdings