A group of investors is pooling millions of dollars in cryptocurrency in an attempt to purchase a rare, first-edition copy of the U.S. Constitution being auctioned off at Sotheby’s this week.

The organization, ConstitutionDAO, is seeking to purchase one of the 13 surviving official copies of the Constitution. Sotheby’s, the auction house holding the sale, pegs the sale at between $15 and $20 million.The auction is scheduled for Thursday.

ConstitutionDAO...

A group of investors is pooling millions of dollars in cryptocurrency in an attempt to purchase a rare, first-edition copy of the U.S. Constitution being auctioned off at Sotheby’s this week.

The organization, ConstitutionDAO, is seeking to purchase one of the 13 surviving official copies of the Constitution. Sotheby’s, the auction house holding the sale, pegs the sale at between $15 and $20 million.The auction is scheduled for Thursday.

ConstitutionDAO describes itself as a decentralized autonomous organization formed to put the Constitution into the hands of the people, according to its website.

As of Tuesday morning, the group had raised $5.2 million, or around 1,211 ether.

Contributors wouldn’t receive fractionalized ownership of the Constitution, rather they would get a governance token that allows possessors to advise on where the Constitution should be displayed, how it should be exhibited and the mission and values of ConstitutionDAO, the organization said.

The copy was printed for delegates at the Constitutional Convention and for the Continental Congress more than 230 years ago. ConstitutionDAO says it seeks to take the Constitution copy, the only one in private hands, and make it accessible to the public.

“The eventual home must have the expertise to properly house, store, and maintain the artifact,” ConstitutionDAO wrote on its website. “Additionally, the community has expressed strong preferences for institutions that are free to the public and willing to cover the costs associated with housing the document.”

The price of ether slid for a fifth consecutive day on Tuesday, declining another 5% to around $4,300. It is down more than 12% from its latest record but remains sharply higher for the year.

Representatives for Sotheby’s, the auction house, didn’t immediately respond to a request for comment.

Write to Omar Abdel-Baqui at omar.abdel-baqui@wsj.com