Washington (CNN)The first thing you need to know about Steven Mnuchin is it is pronounced "mah nu chin."
Who is Steven Mnuchin, Trump's pick for Treasury secretary?
Trump rode a wave of populist anger at Wall Street, political correctness and the establishment media into the White House, but he's picked a successful banker, who made billions off the housing bubble and now produces Hollywood movies to be his Treasury Secretary.
But it's a job Steven Mnuchin, who served as the finance chairman of Trump's presidential campaign, wanted badly.
He even recruited potential deputies before Trump tapped him.
The Treasury Department has expansive responsibility over business and oversees banking regulations, financial markets and the IRS. It has about 100,000 employees, an estimated 91,000 of them at the IRS, an agency that Trump has said is auditing his tax returns. Both he and Mnuchin would like to drastically simplify the US tax code, particularly for businesses.
Trump has praised Mnuchin, who with the Republican National Committee helped raise tens of millions of dollars for Trump's winning campaign.
The 53-year-old started as a Wall Street insider working for old-line firms before running a series of eclectic businesses -- including his own hedge fund and a West Coast consumer bank.
He told CNBC that tax reform will be his top priority and promised the largest tax overhaul since the Reagan administration.
He has never held public office before, which would make this key economic position his first in the public sector.
During congressional hearings, he can expect tough questions about his actions during the Great Recession. Mnuchin led a group that bought failed subprime lender IndyMac for pennies on the dollar in 2009, about a year after the FDIC took over the California bank following a run on deposits by customers.
IndyMac had become a poster child for the risky home loans that brought on the housing crisis and the meltdown in financial markets. The FDIC agreed to assume much of the losses as part of its sale to Mnuchin, who renamed it OneWest.
But regulators soon questioned OneWest's foreclosure practices, which included so-called robo-signings that pushed homeowners into foreclosure without proper review or due process.
The bank was one of many that agreed to pay millions in fines to compensate customers. Occupy Los Angeles protesters showed up at Mnuchin's Bel Air mansion in 2011. And this month, two fair housing groups in California filed a complaint with the Department of Housing and Urban Development, accusing the bank of discriminating against minority borrowers during his tenure there.
Mnuchin eventually sold OneWest to CIT Group (CIT) in 2014 for $3.4 billion and joined CIT as part of the deal. When he left CIT less than two years later, he received a $10.9 million severance package.
Mnuchin is a twice-married father of three who graduated from Yale. Like his father, he was a partner at Goldman Sachs. He worked for the firm for 17 years, joining at age 22 and leaving just before his 40th birthday, in 2002.
He later worked for George Soros, the billionaire financier who has bankrolled liberal candidates and causes -- and who was depicted as a villain in Trump's last campaign ad.
But Mnuchin only stayed with Soros a year, leaving in September 2004 to start his own hedge fund, Dune Capital Management.
Mnuchin also worked as a Hollywood producer, putting out films including "American Sniper," "The Lego Movie" and this summer's "Suicide Squad." His latest film, which opened right before Thanksgiving, is called "Rules Don't Apply."
Also, his signature isn't what we would call the most appealing. Mnuchin's signature will appear in the lower right corner of newly printed currency but he's no John Hancock. It's a few disjointed swoops and curves. In this way, he has a lot in common with Lew, whose signature was so bad that President Obama made him change it.
Finally, Mnuchin hasn't always gotten along with Trump. In a 2008 lawsuit, Trump targeted one of Mnuchin's companies in a lawsuit that alleged Deutsche Bank and other investors improperly balked at extending multimillion-dollar construction loans on the Trump International Hotel and Tower in Chicago. The case was settled.