They have an outright market where clients can place wagers on the winner of the fifty-man battle royal. Braun Strowman and Daniel Bryan have been installed as joint-favourites. You can find them both at 4/1.
There are also match odds for the bouts that are scheduled to take place on the card.
Seth Rollins is a 3/5 favourite to still be holding the Intercontinental Championship at the conclusion of the fatal four-way ladder match against The Miz (3/1), Finn Balor (5/1) and Samoa Joe (13/2).
John Cena is 11/20 for his singles match against Triple H (5/4).
WWE Smackdown Tag Team Champions - The Bludgeon Brothers - are 1/3 for the defence of their straps against former titleholders, The Usos (2/1).
The Undertaker and Chris Jericho are also booked to wrestle in a casket match on the night. Taker is a 1/2 favourite while Jericho - who has replaced the originally listed Rusev - is 7/5.
WWE Universal Champion, Brock Lesnar, is 5/2 to overcome Roman Reigns in a steel cage match. If you think Reigns will finally get the W against Lesnar, you're looking at 1/4.
The Greatest Royal Rumble will take place from Saudi Arabia on Friday April 27th.