Bitcoin prices have taken off in the last few days. In recent action, bitcoin rose to $532.13. That’s up about 20% since last Friday’s level of $445.01 according to CoinDesk’s bitcoin price index, which tracks prices on three exchanges. While $500 is a far cry from levels around $1,000, where bitcoin was trading late last year, it’s significant because bitcoin has been hovering in the $400s since late March.