As a professional poker player Dan Bilzerian is used to making large bets.
In 2014 he told US shock jock Howard Stern he'd won $50 million playing poker in the previous 12 months and had once lost $3.6 million in one game.
He's also shown a willingness to gamble away from the tables, challenging Supreme Court lawyer Tom Goldstein to a drag race a few years back and pocketing more than half a million dollars (AUD).
But his latest wager is going to test him like never before.
For reasons that remain unclear, the 35-year-old has bet fellow high-stakes poker player Bill Perkins $800,000 he can ride a bike from Los Angeles to Las Vegas in less than 48 hours.