Previously the benefactor has been Carl Shulman (and Iād guess he is again, but this is pure speculation). From 2019-2020 donor lottery page:
Carl Shulman will provide backstop funding for the lotteries from his discretionary funds held at the Centre for Effective Altruism.
The funds mentioned are likely these $5m from March 2018:
The Open Philanthropy Project awarded a grant of $5 million to the Centre for Effective Altruism USA (CEA) to create and seed a new discretionary fund that will be administered by Carl Shulman
Previously the benefactor has been Carl Shulman (and Iād guess he is again, but this is pure speculation). From 2019-2020 donor lottery page:
The funds mentioned are likely these $5m from March 2018: