Individuals dominate money in politics, accounting for over 90 percent of campaign contributions, yet studies of drivers of individuals' giving are scarce. We analyze data on all contributions made between 1991 and 2008 by all 1,556 people who became S&P 500 CEOs during that interval. We exploit variation in leadership status over these individuals' careers to identify that being an S&P 500 CEO causes a $4,029 or 137 percent jump per election cycle in personal giving. While some fraction of CEOs' contributions can be attributed to long-standing preferences, the striking changes in behavior cannot be explained by these factors alone. (JEL D72, G34)