The estimated jackpot for Wednesday night’s Powerball was at $450 million to begin the day on Wednesday. By mid-day, that number had soared to $500 million.

Sally Lunsford from the Kansas Lottery tells KSAL News that the estimate is based on sales and activity across the country.

No one has won  Powerball’s biggest prize since Nov. 4. The jackpot now is the sixth-largest ever in North America, and if there is no winner after Wednesday night’s drawing, the prize will keep climbing.

The biggest jackpot was a $656 million Mega Millions prize won in 2012. The last time  Powerball had grown this large was in February 2015, when three winners split a $564.1 million prize.

Powerball  is played in 44 states as well as the District of Columbia, U.S. Virgin Islands and Puerto Rico.