Just before 4am its value was at $654.08 - up from $563.92 at 5pm yesterday, according to Coinbase.
The pound was taking its worst battering in years after it fell more than seven per cent against the dollar to $1.3783, and 5.2 per cent against the euro to €1.2390. It lost 20 cents against the dollar in a little over three hours - a historic fall.
"It's definitely tin hats time," said Joe Rundle, head of trading at ETX Capital.
"If Leave wins there will be carnage for cable."
After just over 220 results had come in, Leave was at 51.9 per cent of the vote, while Remain was at 41.1 per cent. A leading political forecaster put the chances of the UK remaining in the European Union at zero per cent - suggesting Friday will be one of the most important political days in history for the UK.
|Brexit Britain: What you need to know|