JPMorgan CEO Jamie Dimon has been one of the most vocal critics of Bitcoin and other cryptocurrencies in the financial industry. The banking titan regularly takes to the airwaves and the newspapers to denounce Bitcoin as a Ponzi scheme, warning of its upcoming collapse. If Dimon's thesis is right (and many experts doubt that it is), his timing certainly isn't. He's been warning of an imminent collapse in the value of Bitcoin since November 2015. Since then, the value of the virtual currency has jumped more than tenfold. In the same time, the US stock market, in which JPMorgan and other financial institutions place astronomical amounts of their clients' investments has increased by only 40%. Even if Dimon genuinely believes that a crash is coming, his investors have missed out on enormous potential returns by not getting onboard the train.Yet, Dimon's words have not weakened despite the continuing rise of Bitcoin. In the last week, despite promising that he was "bored" of talking about Bitcoin and promising to avoid the topic of discussion in future, he couldn't help but continue to mention it. In wide-ranging remarks, he described it as "stupid", having previously labelled the cryptocurrency as "a poor store of value" and predicting that the Bitcoin story "won't end well". Dimon seems unlikely to eat his words, regardless of the overall performance of Bitcoin in the coming years. To him, bashing Bitcoin seems to have become a personal cause and where other financial titans have cautiously welcomed the emergence of new trading options (after all, trading is what makes them money), Dimon has continued to rail against the very idea of Bitcoin. While this level of nervousness is understandable, it is at the very least curious that a well known financial titan takes so much time out of his day to say negative things about a small part of the financial world.