U.S. President-elect Donald Trump speaks during a USA Thank You Tour event at Giant Center in Hershey, Pennsylvania, U.S., December 15, 2016. Lucas Jackson/Reuters President-elect Donald Trump's nomination on Monday of Vinnie Viola for secretary of the Army lifted the combined net worth of his top team of officials and advisers to more than $10 billion.

Viola, the founder of the high-speed-trading firm Virtu Financial and owner of the NHL's Florida Panthers, is estimated by Forbes to be worth $1.8 billion.

Some of Trump's wealthiest picks for key positions include Betsy DeVos, his choice for secretary of education, worth $5.1 billion, and Wilbur Ross, the nominated secretary of commerce, who is worth $2.5 billion.

Additionally, Trump tapped ExonnMobil CEO Rex Tillerson, worth at least $228 million, to be secretary of state. Steve Mnuchin, Trump's pick for Treasury secretary, is worth at least $100 million, according to estimates.

Similarly, Gary Cohn, the former chief operating officer at Goldman Sachs, has been appointed to a cabinet-level position as National Economic Council director. He had Goldman shares worth $210 million at the time of his appointment.

Together, the combined net worth of DeVos, Ross, Tillerson, Mnuchin, Viola, and Cohn tops $10 billion.

Steve Schwarzman, chairman of Trump's economic advisory forum, is worth an estimated $11 billion.

The president-elect said he chose super-wealthy people and company executives for key positions because they would be able to use their experience to negotiate on behalf of Americans.

"These people have given up fortunes of income in order to make $1 a year, and they're so proud to do it," Trump said earlier in December during his Thank You tour.

While campaigning, Trump promised to "drain the swamp" of Washington insiders and lobbyists who he said profited at the expense of hardworking Americans.

His subsequent picks, which include two former Goldman Sachs executives, have raised eyebrows about his pledge.