The mega-rich donated heavily in 2014, with the 10 largest single donations totaling $3.3 billion.
The top donation of the year was a $1-billion bequest from the late Ralph Wilson Jr., a Detroit businessman who owned the Buffalo Bills football team, to his own charitable foundation.
No. 2 came from businessman Ted Stanley, who gave $650 million to the Broad Institute for research on the genetics of psychiatric disorders. It was one of the biggest donations ever to mental health research.
The top 10 list, released annually by the Chronicle of Philanthropy, ranks publicly announced single charitable gifts by size as opposed to the most generous donors overall.
The donations are from individuals or their foundations and were made to U.S. nonprofits and research institutions. The tally does not include donations of artwork or gifts from anonymous donors.
The robust stock market, plus other strong economic signs, helped boost charitable donations not just by billionaires but also by multimillionaires, the Chronicle said. According to the Washington, D.C., publication's data, publicly reported donations of $1 million or more totaled nearly $11 billion in 2014, compared with $9.6 billion the year before.
"When the economy is good, people feel very comfortable about giving," said Stacy Palmer, editor of the Chronicle. "We saw that last year and we're seeing it this year that the very rich are giving generously again."
Despite the sizable contributions, charitable donations have yet to recover to the sums that the super-wealthy donated before the economic downturn.
In 2007, the 10 biggest gifts totaled $4.1 billion, compared with 2014's $3.3 billion and 2013's $3.4 billion. Even so, the last two years have been much stronger than the years immediately after the financial crisis, when the totals struggled to exceed $2.5 billion.
After a blockbuster year for tech giving in 2013, Silicon Valley elite took two spots on the latest top 10 list: GoPro founder Nick Woodman and his wife, Jill, were third on the list with a $500-million donation to the Silicon Valley Community Foundation, and Google co-founder Larry Page was No. 5 with a $177.3-million gift to the Carl Victor Page Memorial Foundation.
In 2013, the largest single donation came from Facebook founder Mark Zuckerberg and his wife, Priscilla Chan, who donated 18 million shares of Facebook stock that was valued at nearly $1 billion to the Silicon Valley Community Foundation. That marked the first time philanthropists under 30 had made the biggest contribution, the Chronicle said.
Palmer said the Zuckerberg-Chan donation was initially viewed as a possible aberration because such large donations historically come from much older people.
But the large 2014 gifts by the Woodmans and Page — Nick Woodman is 39 and Page is 41 — show a tech-driven shift in the way wealthy people are thinking about charity, she said.
"Having people break into the top 10 who aren't even in their 40s is a big deal," she said. "What's really great to see is that some people are thinking about it much earlier in their careers."
In February, the Chronicle of Philanthropy plans to release its annual ranking of the 50 most generous donors, a list based on total donations, not just single gifts and not just those announced to the public.