Today there are nearly four times as many Americans worth $50 million or more than there were just a decade ago. Many of these ultra-wealthy people are giving big to charity and earning a spot on the Chronicle’s Philanthropy 50, an annual ranking of the most generous donors in the nation.

Some of these megadonors surprise charities with bequests they never sought. But in many cases savvy fundraisers have figured out how to capture the attention of these low-profile multimillionaires and billionaires.

Unfortunately, small nonprofits may never see much of this largesse, and donors of modest means could decide to give less as they see huge gifts flowing to their favorite charities. How can charities best navigate the growing wealth gap as they seek to attract more money to fuel their operations?

Join the Chronicle and our panel of experts to explore these and other big-giving trends and gain insights into how the most successful nonprofits are attracting some of the largest gifts in their histories.