https://techcrunch.com/2018/01/26/coincheck-nem/

A Japanese cryptocurrency exchange has claimed it lost more than $400 million in tokens following an alleged hack on its service.

Coincheck said Friday that some 500 million tokens of NEM, worth around $400 million at the time of writing, according to comments at a press event attended by Bloomberg. NEM, the tenth largest cryptocurrency based on total coin market cap, is a distributed ledger platform primarily aimed at enabling payments and other financial services.