Bitcoin has just punched through $US17,000 ($22,580) on the Bitcoin platform and some Americans are now taking out mortgages to buy into the cryptocurrency mania, CNBC reports.

"Bitcoin is in the 'mania phase, with some people even borrowing money to get in on the action," Joseph Borg, president of the North American Securities Administrators Association, told CNBC.

"We've seen mortgages being taken out to buy bitcoin. … People do credit cards, equity lines," said Borg, who is also director of the Alabama Securities Commission.

The price of Bitcoin has just shot through $US17,000. Chris Ratcliffe

"This is not something a guy who's making $US100,000 a year, who's got a mortgage and two kids in college ought to be invested in."

Bitcoin has been on a tear this year, starting at $US1000 and rocketing above $US19,000 last week on the Coinbase exchange. "The price on Coinbase, which accounts for a third of bitcoin trading value, is often at a premium over other exchanges," CNBC says.