Bitcoin surges towards $17,000 as concerns mount

Bitcoin flirted with $17,000 on Thursday, triggering a warning the cryptocurrency was “like a charging train with no brakes” and prompting fresh concern about its looming launch on mainstream markets. Still under $14,000 in Asian trading hours, it smashed through $15,000 in European trading and then later surged to $16,777.08 around 1630 GMT, according to Bloomberg…