Barack Obama and Mitt Romney are both billion-dollar men. The presidential candidates, with the help of their respective parties, are each on track to raise more than $1 billion by Election Day, according to financial disclosures filed by their campaigns on Thursday. By Oct. 17, with just over two weeks to go to the election, the Democrats have raised $1.06 billion for Obama, while Republicans collected $954 million for Romney. The stark difference, however, is the source of the funds. Wall Street, super PACs, and an establishment of business leaders contributed heavily to Romney’s campaign, while Obama has relied on Silicon Valley, retirees, and small donors—roughly 55 percent of Obama’s funds came in donations of less than $200.