A top transition source told NBC News that he could be named as soon as Wednesday.
Mnuchin, who served as finance chairman for Trump's presidential campaign, was last the chairman of Dune Capital Management. Mnuchin's firm's Hollywood financing has helped to fund James Cameron's "Avatar," among other blockbusters. He previously spent 17 years at Goldman Sachs, worked at Soros Fund Management and co-founded OneWest Bank Group.
The possible appointment of Mnuchin, an alumnus of one of the world's most powerful financial institutions, seems to clash with Trump's populist campaign rhetoric and pledge to be the "voice" for downtrodden blue-collar workers. Mnuchin would take the helm of a Treasury that could take a starkly different approach than the department did under the Obama administration on taxes, trade and financial regulation.
It is not entirely clear how much Mnuchin's personal views align with the financial priorities Trump has outlined for his United States. Mnuchin, like Trump, donated heavily to Democratic candidates before this cycle. Like Trump, his economic standing has little in common with the economic populism that helped to propel Trump to the White House.