The US Powerball lottery jackpot is expected to rise to at least $1.3bn (£895m) after a 19th draw without a winner on Saturday night.
It means Wednesday's jackpot will be a world record.
No one matched the numbers - 32, 16, 19, 57, 34 and Powerball number 13 - for the prize of almost $950m (£654m) which was up for grabs on Saturday.
Players must match all six numbers to win the jackpot.
The first five can be in any order but the sixth must be the Powerball.
Before this rollover sequence the record was a $656m (£451m) Mega Millions jackpot won in 2012 by three tickets.
The total could grow even larger as people race to buy tickets.
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The current jackpot started out as $40m (£27.5m) in November, but has ballooned thanks to huge ticket sales as the potential reward grew.
The new jackpot is larger than the gross domestic product for a number of nations, including the Caribbean islands of Antigua and Barbuda.
The Multi-State Lottery Association changed the rules last year to make the odds of winning 292.2 million to one.
However, the group said it expected 75% of all possible number combinations would have been bought for Saturday's draw.
The draw is played in 44 states, as well as the District of Columbia, the US Virgin Islands and Puerto Rico.