Stewart Paperin is a career investor and left-of-center philanthropy manager. He is the managing director of LionRock Partners and the Leopard Rock Property Group, which invests in a variety of ventures, most notably real estate.
Paperin previously spent years working for and overseeing organizations within the Open Society Network, the international grantmaking and activist collective funded and led by left-of-center financier and political donor George Soros. 
Stewart Paperin was the president of Brooke Group International, a joint British-Russian investment firm, from 1989 to 1993. During this period, the Soviet Union collapsed, and state industries were rapidly privatized with the involvement of Western multinational corporations, resulting in a period of severe economic recession, political instability, and decline of living standards in Russia. As the head of Brooke Group, Paperin oversaw the introduction of the international money transfer service Western Union to Russia, as well as the privatization and acquisition of Russian lumber and chemical firms.  Paperin would go on to sit on the boards of Western Union and OAO Svyazinvest, Russia’s national telephone company. 
Paperin has worked for the investment firm LionRock Partners and its affiliate, the Leopard Rock Property Group, since 2003. His work with these firms, which eventually led to him becoming the managing director, has mainly been focused on investments within the United States, particularly involving real estate in New York and California. 
In 1996, Paperin went to work for the Open Society Foundations (OSF) – the flagship grantmaking organization within the Soros Network. He would remain with the OSF for 17 years, eventually rising to the position of executive vice president. Paperin’s primary responsibilities included managing the foundations’ finances and real estate acquisitions, as well as consulting the chairman. 
Two years after joining OSF, Paperin also began working for the Soros Economic Development Fund (SEDF) – a grantmaking organization within the Open Society Network which serves as a pass-through for funding from other entities within the network, and the related Soros Fund Management (SFM). Paperin’s involvement with these Soros funds also marked a return to his involvement in Russian financial affairs: as a senior advisor to SFM, he worked to extract more profit from Soros’ investments in Russia, particularly in the telecommunications and fossil fuel industries. During his 16-year stint in the Soros investing sphere, Paperin rose to the position of president of the SEDF, and after departing in 2014, he remained involved with the fund as president emeritus. 
According to Paperin, George Soros personally invited him to help scale up the SEDF and come on board as its chief financial officer. Paperin would go on to oversee Soros’ major investments in Eastern Europe, where the SEDF took advantage of the ongoing privatization of state-owned industries. 
As SEDF president, Paperin advocated for global finance firms to invest in farmland, particularly in developing countries like Ghana and Zimbabwe. In a 2014 interview with CNBC, Paperin claimed that the SEDF did not view profit from such investments as the main priority and said that the fund allegedly makes “whether there’s a social benefit” its “first test for a potential investment.” 
Stewart Paperin sits on the board of directors of the Climate Policy Initiative, an environmentalist policy development and advocacy organization. He has also held board positions at numerous major international corporations, including the PennOctane Corporation, a fossil fuel giant, as well as the money transfer provider Western Union and several telecommunications firms.