Someone out there just made a bet that bitcoin will surge above $50,000 next year, trading data show—about triple its current price.

Daily trading records released Wednesday by LedgerX, a startup electronic market for bitcoin derivatives, show that an unidentified trader or traders entered the bullish bets using bitcoin call options that expire next December. The trade wagering on a move to $50,000 was the first of its kind on LedgerX.

Just under $1 million was paid for the options in one or more trades that took place during the 24-hour period ending at 4 p.m. Eastern Time on Wednesday, the records show. It is unclear from LedgerX’s data who the buyer or buyers were or whether the purchasing was done in multiple transactions or just one.

If bitcoin is below $50,000 on Dec. 28, 2018, the options will expire worthless, and the $1 million will be lost. If bitcoin rises above that level, the options will give their owners the right to buy 275 bitcoins for $50,000 apiece—a transaction that would cost about $13.8 million.

Such a trade could be lucrative if the digital currency skyrockets to $500,000 or even $1 million or more—something some of bitcoin’s most enthusiastic supporters say will happen.