Bitcoin made something of a surprise comeback Tuesday (April 2).
The cryptocurrency suddenly soared by as much as 20 percent.
That was its biggest one day jump in a year.
It took the electronic currency above 5,000 dollars for the first time since November.
The cause of the jump not certain.
But analysts say it appears there was a huge order for Bitcoin by a mystery buyer.
Exchanges in the U.S. and Luxembourg seem to have processed a single purchase worth about 100 million dollars.
Experts couldn't point to any specific news or development in the crypto sector that could explain the move.
Bitcoin surged to near 20,000 dollars in late 2017, amid a surge of investor enthusiasm.
But the price collapsed as interest waned.
It's now mainly traded by smaller hedge funds, tech firms and rich individuals.
Bitcoin prices this year had previously been relatively stable at around three to four thousand dollars.