A look at the list of people who have made the Giving Pledge reveals a lot of entrepreneurs and business builders, including FinTech legends, Michael Bloomberg and Tom Secunda.
The wealthiest 400 Americans are worth over $2 trillion. Together, it's been reported they own as much wealth as the bottom half of American households combined.
http://www.cbsnews.com/news/the-giving-pledge-a-new-club-for-billionaires/