Bidding for Blue Origin's first human flight alongside Jeff Bezos and his brother hits $4.5 million

Bidding for a seat on Blue Origin's New Shephard rocket alongside Jeff Bezos and his brother topped $4.5 million on Thursday as the second phase of the online auction comes to a close. 

According to the company's website, the highest bid to ride on the July 20 flight is currently $4.5 million, over a million dollars more than Monday's high bid of $3.2 million.

The identity of the top bidder is not yet known and will not be known until bidding has stopped on June 12, concluding with a live auction.

Bidders need to raise their bid limit by June 10 5PM EST to be a part of the June 12 auction, according to the Daily Mail.