Amount donated in 2012: $423.4-million
Top beneficiary: Laura and John Arnold Foundation
Background: Mr. Arnold founded Centaurus Energy, a hedge fund. Ms. Arnold is a former corporate lawyer and former businesswoman.
Mr. Arnold, 38, and Ms. Arnold, 39, gave more than $251.2-million to their Laura and John Arnold Foundation, which they established in 2008 to support nonprofits and programs working to improve the criminal-justice, K-12 public-education, and pension systems. Including their most recent donation, the Arnolds have put more than $900-million into the fund.
The foundation awarded about $70.1-million to charitable causes last year, including a total of $25-million in grants to two groups to establish and expand charter schools in New Orleans: the Charter School Growth Fund and New Schools for New Orleans. The foundation also gave $4.8-million to the Nutrition Science Initiative for obesity research and $2.1-million to the Giving Library, an online forum to help philanthropists learn about charities. The foundation created the library in 2012.
In addition to the money the Arnolds put into their foundation last year, they also gave a total of nearly $172.2-million to a variety of education groups, nonprofits that work in the criminal-justice system, public-accountability organizations, and others.