The coming election cycle will likely be the most expensive in history. Thanks to Citizens United and other recent court decisions, individuals, corporations and unions can make unlimited donations to so-called super PACs that support a candidate. The money is flowing in. So, exactly who is donating, and what do they want?

Here’s our guide to the top 10 super PAC contributors through Jan. 31, the latest date for which donors have been required to disclose. Unless otherwise noted, all estimates of net worth are from Forbes. (See our PAC Tracker for an interactive breakdown of all the money going to super PACs and others.)