Donor-Advised Funds Continued to Set Records in 2017, NPT Reports

At the same time, the average size of DAF accounts decreased by 20.5% from 2016 to $237,356. The report said the reason for the decrease was the historic growth in number of DAF accounts.

The annual report, NPT's 12th, mainly used data from IRS Form 990 filings to analyze the DAF market. Researchers examined 1,002 charitable organizations that sponsor DAFs, including national charities, community foundations and other sponsoring charities.

"Growth in donor-advised funds reflects the charitable instinct Americans, who are among the most generous donors in the world," Eileen Heisman, president and chief executive of NPT, an independent DAF sponsor, said in a statement.

"Tax reform drove many to 'pre-fund' their philanthropy in 2017 when the value of their tax deduction could be higher. A booming stock market and a tense political climate spurred generosity and helped donors support the values and causes they embrace."

Heisman said growth in grants from DAFs to charities of all sizes have outpaced contributions for four out of the last five years. "We predict that grants from DAFs to charities will exceed $20 billion in 2018."

NPT said that its report for the first time included a brief analysis of the types of assets contributed to DAFs. Researchers compiled a data set representing 61.5% of the total contributions in 2017, some 60% of which were non-cash assets.

"The vast majority of non-cash asset contributions are publicly traded securities, but we also see donors turning their business interests, real estate, fine art and jewelry into charitable capital," Heisman said. "We anticipate contributions of illiquid assets will continue to increase in the coming years."

(Related: America's Top 10 Favorite Charities)