Since President Donald Trump took his seat in the Oval Office in 2017, America's billionaires have become 10.6% richer.

That's according to the left-leaning Institute for Policy Studies' "Billionaire Bonanza" report that analyzed wealth data from the Bloomberg Billionaire Index and Forbes' Global Billionaires and 400 lists since 1990.

It found that the combined wealth of America's 565 billionaires in 2017 stood at $2.7 trillion, according to that year's Forbes Global Billionaires list. By 2020, the number of America's billionaires had increased to 614 and their collective wealth to $2.9 trillion, based on Forbes' most recent list calculated on March 18, 2020.

But by April 10, according to the Billionaire Bonanza report's analysis of Forbes' daily net worth updates, the number of American billionaires had increased by another 15 people to 629, surging their overall net worth up to $3.2 trillion — a gain that occurred over the course of 23 days during the coronavirus pandemic.

It's likely that Trump's tax reform law — formally known as the Tax Cuts and Jobs Act (TCJA) — passed at the end of 2017 played a role in this three-year wealth growth. While Americans at all income levels, on average, received a tax cut, the benefits were tilted towards the rich who'd see larger average tax cuts as a percentage of after-tax income, Business Insider's Bob Bryan reported, citing a report from the nonpartisan Tax Policy Center (TPC).

While America's richest have collectively watched their billions growth, household wealth has remained relatively flat over the past 30 years, according to the Billionaire Bonanza report, which cited Fed Reserve data. The median household wealth in 1989 was $101,820; in 2016, it was $107,619.

The wealth gap is related to "dynastic wealth"

The gap between the rich and the poor had widened to a record high in 2018 since the US Census began tracking it 50 years ago, reported Taylor Telford for The Washington Post, citing US Census data. The chasm is most prevalent in wealthy coastal states and areas with "widespread poverty," Telford wrote.

Many consider generational wealth to be one of the key causes behind this growing economic gap. Consider Warren Buffett, who has been vocal about his efforts to reduce the vast wealth sitting in the hands of a few influential people. "Dynastic wealth, the enemy of a meritocracy, is on the rise," he said during a Senate Finance Committee hearing about the federal estate tax in 2007. "Equality of opportunity has been on the decline."

It's why he and Bill and Melinda Gates created the the Giving Pledge, in which billionaires have pledged to give away most of their money instead of keeping it in the family.

"A lot of folks don't like to acknowledge the big leg up they get in things like buying a house or avoiding significant student debt as a result of generational wealth," Josh Hoxie, director of the Project on Opportunity and Taxation at the Institute for Policy Studies, previously told Business Insider.

"That leads to big problems when other people who don't have generational wealth look around and wonder why they're so far behind," he continued. "The reality is that the top indicator for economic prosperity is not hard work or intelligence, it's the family you're born into."