Study authors Moore and Christin identified 40 Bitcoin exchanges worldwide that convert the cyber money into 33 hard currencies. Of those 40, 18 have gone out of business. Nine of the 40 experienced security breaches from hackers or other criminal activity, forcing five of them to subsequently close. Another 13 closed without any publicly announced breach. From their study, the researchers found the failure rate of Bitcoin exchanges is 45 percent. The median lifetime of an exchange is just over one year, 381 days.