Investing.com – A South Korean cryptocurrency exchange filed for bankruptcy after it was hacked for second time this year, highlighting concerns about security as trade in bitcoin and other virtual currencies boom.The exchange, called Youbit, announced on its website Tuesday that it had been hacked, causing a loss worth 17 percent of its total assets.That was the second hack this year after a cyber attack in April when nearly 4,000 bitcoins were stolen.Youbit did not elaborate on the amount, but said all customers' cryptocurrency assets will be marked down to 75 percent of its value, adding it has stopped trading and will work to minimize customer losses.Separately, South Korea's Financial Supervisory Service said Tuesday it does not consider bitcoin and other cryptocurrencies to be currencies of any kind and would not seek to regulate their trade beyond rules announced last week."All we can do is to warn people as we don't see virtual currencies as actual types of currency, meaning that we cannot step up regulation for now," FSS governor Choe Heung-sik said at a press conference.
