According to Dune Analytics, as of March 12th, the total assets under management (AUM) of Grayscale Bitcoin Trust Fund (GBTC) plummeted to $28.5 billion, with Grayscale currently accounting for 48.9% of the total assets of 10 US Bitcoin ETFs holding $56.7 billion. Since the US spot Bitcoin ETF began trading on January 11th, Grayscale's share in the Bitcoin ETF market has fallen below 50% for the first time.