But his surprise victory could be a major win for the big banks he has criticized. Republicans, who retained control of the House and Senate, could repeal major parts of Dodd Frank regulatory reform, which attempted to rein in big banks after the 2008 financial crisis, and weaken the Consumer Financial Protection Bureau, industry analysts said.
"Republicans, who have railed against the CFPB for five years, will try to strip much of its authority," Ian Katz, an analyst at Capital Alpha Partners said in a note to investors. "One of the key questions is how far Republicans will go to gut Dodd-Frank."
It may be too early to tell how a Trump presidency will affect the debate surrounding the CFPB, said Andrew Sandler, chairman of the BuckleySandler law firm. Trump ran a populist campaign and the consumer agency may be popular with his followers, he said.
“We know that there is likely to be changes to Dodd Frank, but we don’t know whether it will impact CFPB” yet, said Sandler.
Major banks stocks jumped in early trading Wednesday. Goldman Sachs was up more than 2 percent, while JPMorgan Chase was up more than 3 percent.
Wall Street insiders had been preparing for a tough year under a Clinton administration, including a push by Democrats to institute a financial transaction tax, which would require high-frequency traders to pay a fee every time they buy or sell a stock or bond. That all now appears to be off the table.
“We have no reason to believe President-elect Trump is in favor of anything but the cost-effective, efficient markets we have in America today. We don't need to make our markets great again. They're already great," Bill Harts, president of Modern Markets Initiative, which represents high-frequency traders.
Trump’s relationship with Wall Street is complicated by decades of name-calling, lawsuits and big debts. He has sued Deutsche Bank, blaming the megabank for the financial crisis, but continued to rely on it to finance major projects. When his companies filed for bankruptcy, he bragged, it was the big banks that endured big losses — not him.
But when he put together his economic team, he tapped several high-profile Wall Street figures, including hedge fund billionaire John Paulson. Steven Mnuchin, Trump's national finance director, is chief executive of the hedge fund Dune Capital Management and previously worked at Goldman Sachs.
And while Trump has said he would eliminate the so-called "carried interest loophole" that allowed financiers to pay a lower tax rate on their income, tax experts say his proposals could leave private equity and hedge fund manager paying even less.