Financial services company T-Rex Group has filed to create an exchange-traded fund (ETF) using MicroStrategy (MSTR) shares in the United States. Experts warn about the possible high volatility of such a fund. MicroStrategy, founded in 1989, is now one of the largest holders of Bitcoin, with 214,400 BTC on its books, worth $13.2 billion. MicroStrategy shares are up 120% year to date, thanks to a significant rise in the price of Bitcoin. 📈