As reported by Politico,
Sen. Elizabeth Warren (D-Mass) in a statement late Tuesday: “Steve Mnuchin is the Forrest Gump of the financial crisis — he managed to participate in all the worst practices on Wall Street. He spent two decades at Goldman Sachs helping the bank peddle the same kind of mortgage products that blew up the economy and sucked down billions in taxpayer bailout money before he moved on to run a bank that was infamous for aggressively foreclosing on families.
“His selection as Treasury Secretary should send shivers down the spine of every American who got hit hard by the financial crisis, and is the latest sign that Donald Trump has no intention of draining the swamp and every intention of running Washington to benefit himself and his rich buddies.”
Business Insider added some further context,
Warren's comparison of Mnuchin is to the 1994 Oscar-winning film Forrest Gump, in which Tom Hanks stumbles in and out of historical moments from the 1960s onwards as the eponymous Forrest.
... But I'm still not entirely sure what the comparison is meant to convey. Perhaps it's been too long since I saw the movie, I remember Forrest as an easygoing harmless sort of person, certainly not someone who would "send shivers down the spine". Did Forrest Gump cause something bad that I'm forgetting? What exactly is she trying to say about Mnuchin?