The stock market has jumped, taking many prognosticators by surprise, in anticipation of the seismic changes Mr. Trump has promised: a repeal or refashioning of the Affordable Care Act, a dismantling of the Dodd-Frank regulations for Wall Street, a substantial haircut for corporate and personal income tax rates, and a major infrastructure spending program, among other things.
While the new conventional wisdom may be that the nation is about to see comprehensive change, the truth is that it is likely to be more incremental than across the board.
Take, for instance, the Dodd-Frank Wall Street Reform and Consumer Protection Act. While you would think much of the finance industry would salivate at the chance to rid itself of the law, its view is more nuanced. Most companies have made large investments and changes in their business practices to comply with the law. So it's hard to see how even the law's die-hard opponents in the industry would press for the full repeal that Mr. Trump said he would pursue.
"That omelet has been made; that toothpaste is out of the tube," Lloyd C. Blankfein, the chief executive of Goldman Sachs, said at the conference.
"I wouldn't want regulation to be repealed in toto," he added. "If you want to be good for bankers, you have to have policies that would be good for economic growth."
More likely than a repeal, Mr. Trump's administration will try to eliminate the components he has criticized most. A Trump administration could try to weaken the Consumer Financial Protection Bureau, the watchdog agency created by Dodd-Frank, which Republicans loathe, for example.
"The C.F.P.B. probably won't be eliminated," Ian Katz, a research analyst at Capital Alpha Partners in Washington, wrote in a note to clients. "It would be horrible politics and optics to get rid of an agency that was established to protect the little guy."
Mr. Katz predicted that the Trump administration would be able to push through a switch that critics of the agency have long lobbied for: a shift in control of the consumer bureau from a single director to a bipartisan commission.
Mr. Trump might also focus on changing a rule for small banks that grow to more than $10 billion in assets. Currently, such growth catapults a bank into a new regulatory category, one that comes with much stricter scrutiny and more elaborate reporting requirements. This rule has been criticized by the banking industry as an impediment to growth and competition.
As for the return of Glass-Steagall — something Mr. Trump has talked about — don't bet on it. "The Republican Party's call for a return to a division of commercial and investment banking shouldn't be taken seriously," Mr. Katz wrote. "That was part of a campaign document. Big banks are useful as a populist scapegoat, and Trump may continue to use them in that way. But neither he or his top aides are interested in Glass-Steagall 2.0."
Piecemeal change may also be true of Mr. Trump's pledge to undo Obamacare, which was one of his bedrock campaign promises.
Mr. Bertolini of Aetna predicted: "There will be a repeal first, and I think the repeal will be at a minimum in name."
It's nearly impossible for the law to be replaced with the flip of a switch. "Because what's going to happen in the next year?" he said. "We have people signed up; we have to honor that through 2017. We'll have to work quickly to have something for 2018."
Mr. Bertolini said that whatever replacement plan might materialize, the government was not going to just stop insuring the 20 million or so people who are covered under the Affordable Care Act. "You can't put them out on the street without insurance," he said. His expectation is that Medicare Advantage will be expanded.
The backpedaling on the "repeal" pledge has already begun: Mr. Trump has said in the past several days that he intends to make sure that health insurers will not be able to turn away people with pre-existing conditions, and that people under the age of 26 will still be able to have coverage under their parents' plans.