The architect of the company’s audacious Bitcoin-hoarding strategy explains why he calls the crypto “a flow of money from the 20th century to the 21st century.”

Shares in MicroStrategy, the largest corporate holder of bitcoin, initially jumped and then fell Monday after the software company said it had bought $5.4 billion of the cryptocurrency.

Bernstein analysts predict MicroStrategy will own 4% of the total bitcoin supply by the end of 2033, an amount they expect to be worth about $830 billion.