At the end of a day when incoming and outgoing presidentstussled over the fate of U.S. health care, it was the words of VicePresident-elect Mike Pence that seemed to matter most to anxiousinvestors.

Pence, in a visit to Congress, sought to ease concerns that arepeal of Obamacare would be done so abruptly that itleaves millions of Americans without insurance and throwshealth-care companies into chaos across the country. He toldreporters that he was talking with Republican leaders to coordinate“both a legislative and executive action agenda to ensure that anorderly and smooth transition to market-based health care system isachieved.”

Earlier in the day, the mood was more strained. President-electDonald Trump, calling Obamacare “a disaster” onTwitter Wednesday, urged Republicans not to take the blame for thelaw as they start a process to change it. Meanwhile, PresidentBarack Obama urged Democrats on Capitol Hill to resist efforts torepeal his signature domestic policy achievement.

“It will be important that we are careful in how we do that,”Pence said at a news conference with House Speaker Paul Ryan.

Enormous challenges remain, including debate within the GOP overhow quickly to proceed with their plans. Yet the remarks senthospital stocks rising on Wednesday, as Community Health SystemsInc., HCA Holdings Inc. and Tenet Healthcare Corp. all had theirbest day of trading since November.

Obama meeting

At the same time, Obama -- in his final weeks in office -- metwith Democrats on Capitol Hill to discuss how to defend theAffordable Care Act from being upended by the unified Republicanpresidency and Congress. The Republican plan would “make Americasick again,” Minority Leader Chuck Schumer said at a newsconference afterward. The administration announced on Wednesdaythat 8.8 million people have so far signed up for coverage thisyear under the law, more than at the same time last year.

Representative Louise Slaughter, a New York Democrat, scoffed atthe GOP’s repeal strategy, saying, “You wouldn’t think of tearingdown a house before you have a new one.” Asked whether she intendsto work with Republicans on a replacement, she said no.

New York’s Schumer told reporters that Democrats’ position isthat Republicans must first put forth a replacement plan. ThenDemocrats will respond and decide their next step.

“I think we have unanimity in our caucuses on that position,” hesaid.

Pence told Republicans during their private meeting that Trump,on his first day in office, plans to take action on Obamacarethrough executive orders aimed at making sure the insurancemarketplace isn’t disrupted by a repeal, according toRepresentative Chris Collins of New York, one of Trump’s earliestHouse GOP backers.

Republicans hope to have a replacement plan on paper in sixmonths, Collins said.

GOP split

There are GOP divisions on what steps to take first. Some wantto see a full health care program before voting to repeal the law,and others want to repeal it first and work on replacementafter.

Maine Republican Senator Susan Collins, a moderate, toldreporters she would like to see a “detailed framework for whatreplacement is going to include as we are moving toward repeal.”She said she would look at a replacement policy before giving hervote to repeal efforts.

“I want to make sure that we don’t have a gap that leaves peoplewho have coverage without coverage” after repeal, Collins said.

A leading House conservative, Representative Jim Jordan of Ohio,said he wants repeal done quickly. “I don’t want that to turn intosome 2, 3, 4-year phase-in,” he said.

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