Mystery surrounds the cryptocurrency exchange company, Bitfinex, whose platform has suddenly morphed into something resembling a private members club. As of December 19th, new users are being asked to enter an enigmatic \"invitation code\" in order to open a new account. No prior announcement was made by the company, nor any information provided about how or where to obtain such a code. The only relevant message that appears on the sign-up page says that \"Due to extraordinary demand, new accounts require an invitation code.\"

To date, there is no indication in forums or public sites to suggest that any new user might have successfully registered since the implementation of this strange new requirement. In the mass confusion, many users are turning to Reddit and helpdesk sites to obtain any available information on how to get a code.

The block on new users might well be a response to the massive escalation in market trading provoked by the entry of Chicago\'s futures markets into the field in the past weeks. Many exchanges have simply been overwhelmed by the volume. Bitfinex had already tweeted about DDoS server attacks on December 17th, and previously warned their users about telephone scammers asking for account information – both of which might have contributed to the invitation code decision.