The iShares Bitcoin ETF (IBTC), ProShares Bitcoin Strategy ETF (BITO), and Fidelity Wise Origin Bitcoin Fund (FBTC) are some of the biggest Bitcoin ETFs in the industry. Most recently, data shows that the IBTC and FBTC are the fastest-growing funds in the world with over $4.2 billion and $2.3 billion in assets, respectively. So, which