A Super PAC working to elect former Vice President Joe Biden is being bankrolled by a bevy of real estate, financial, and oil interests.

Unite the Country, which is run by a lobbyist and longtime Biden confidant, disclosed its donors on Friday in filings made public with the Federal Election Commission (FEC). Between launching at the end of October and the December 31 filing deadline, the group raised more than $3.7 million in support of Biden’s candidacy. Although the money poured in from a number of high-dollar donors, some of Unite the Country’s largest contributors were individuals tied to real estate, Wall Street, and the fossil fuels industry.

The Super PAC’s most prolific donor by far was George Marcus, the leader of one of America’s largest commercial property brokerage firms. Marcus has been a longtime backer of the former vice president, donating to his campaign and even hosting a ritzy fundraiser on his behalf in San Francisco, California. After having maxed out to Biden’s official campaign, the billionaire real estate magnate found a new avenue with which to support Biden. In total, Marcus has donated one million to Unite the Country throughout the end of December 2019. It remains unclear, though, if he donated more since the end of 2019. FEC reports for the first month of 2020 will not be released until mid-February.

Marcus was not the only big name from the real estate world to underwrite Unite the Country’s efforts. Alan Leventhal, the chairman of the Massachusetts-based private real estate behemoth Beacon Capital, is also a top donor. At the end of December, he contributed $250,000 in support of the former vice president’s candidacy.

Unite the Country found similarly strong support on Wall Street. Another important donor is Roger Altman, a longtime investment banker and former deputy secretary of the treasury in the Clinton administration. Altman, who has donated $200,000 to the group, was forced to resign his government post in 1994 over the Whitewater controversy.

Since then, Altman has reinvented himself in high-finance, even helping shepherd General Motors through its bankruptcy in 2009. Altman most recently served as political adviser to the failed presidential campaigns of former Secretaries of State John Kerry and Hillary Clinton in 2004 and 2008, respectively. Now, he seems to be all in for Biden.

Other high-powered Wall Street figures, including Bernard Schwartz and Jonathan Gray, contributed to the Super PAC too. Scwartz, who leads BLS Investments, contributed $100,000 to Unite the Country. Likewise, Gray who serves as the president the Blackstone Group—a private equity giant, gave $50,000. Three senior members of Blackstone’s leadership team contributed a further $50,000 each.

Unite the Country is also bankrolled, in part, by oil interests. Richard Slifka, the chief executive of Global Petroleum Corp., contributed $50,000 to the Super PAC at the end of December. Global Petroleum is a commodity trading company specializing in crude oil and gasoline.

The money from Slifka and others has allowed Unite the Country to spend more than $4.3 million in hopes of creating a last minute surge behind the former vice president ahead of the Iowa Caucuses.