A last-minute frenzy of ticket buying across the United States could see a Mega Millions jackpot swell to a record high of $1 billion by Christmas.
If the rollover jackpot of $586 million goes unclaimed for a 22nd consecutive time today, the next draw could shatter the record of $656 million set in March 2012.
Scott Norris, from Southern Methodist University's mathematics department, said that around 700 million more tickets would need to be sold without producing a winner for the jackpot to hit $1 billion on this run.
He said: "Every dollar you spend on a ticket doesn't make its way into the jackpot. Only about 60 cents in the dollar go into the jackpot and the other 40 go to marketing and state services."
Paula Otto, executive director of the Virginia Lottery and lead director for Mega Millions, said ticket sales are ahead of projections for today's draw, increasing the likelihood it could shatter the current record.