As more institutions embrace the idea of accepting bitcoin as payment, from Tesla to PayPal, criticisms about such a move have grown, especially in light of bitcoin's recent volatile trading. The huge price swings of the cryptocurrency as well as its finite supply are cited as the two main reasons why it does not make an effective method of payment. US Treasury Secretary Janet Yellen is one such critic. Yellen on Monday expressed her doubts about bitcoin ever being used to transact. "I don't think that bitcoin is widely used as a transaction mechanism," Yellen told the DealBook DC Policy Project. "It's an extremely ... (full story)