BlackRock's iShares Bitcoin Trust has become the world's largest original cryptocurrency fund, with total assets reaching nearly $20 billion since its listing in the United States earlier this year. According to data compiled by Bloomberg, this exchange traded fund (ETF) held $19.68 billion worth of Bitcoin on Tuesday, surpassing the $19.65 billion held by the Grayscale Bitcoin Trust Fund. The third largest ETF comes from Fidelity Investment, with total assets of $11.1 billion. (Bloomberg)