Who is going to win the presidential election?

You might want to ask Mark T. Bertolini. He just bet $5.7 billion on President Obama.

Mr. Bertolini is the chief executive of Aetna, which on Monday agreed to acquireCoventry Health Care, a huge provider of Medicare and Medicaid programs. His $5.7 billion bet makes a lot of sense if you believe that the Affordable Care Act - otherwise known as Obamacare - will not be repealed.

Mitt Romney has pledged to repeal the act "on my first day if elected," so any gamble that Obamacare stays intact could be fairly described as a wager that President Obama will remain in office.

At a time when so many in the business community appear to be supporting Mr. Romney, it is telling that some businessmen and investors expect a different result - and are wagering more than rhetoric; they are staking their wallet on it.

It may be counterintuitive, but with the Standard & Poor's 500 up 9.5 percent in the last three months and the stock market over all at its highest point since the financial crisis, there is an argument to be made that investors writ large may be helping the incumbent to win. Intrade, an online market that allows investors to beton political outcomes and other world events, shows that President Obama is favored to win, 57.3 percent to 42 percent.

"The best single predictor of presidential re-election results that we found was the percentage change in the stock market during the three years that preceded Election Day," Deepak Goel of the Socionomics Institute said in February when he released a study that was recently highlighted by Reuters. The study said that recent performance of the stock market was more important than gross domestic product, inflation and unemployment.

At a minimum, the stock market, which is an indicator of future earnings, seems to be in disagreement, at least somewhat, with the steady drumbeat of C.E.O.'s and investors who have said that President Obama's administration, in the words of Daniel Loeb, the outspoken activist hedge fund investor, "is openly hostile to most businesses and unable to articulate or implement policies to spark growth and reduce unemployment."

Mr. Loeb is a frustrated Obama voter who now backs Mr. Romney.

But take a look at some of his most recent investments in the health care field. In the last quarter, he reported in Securities and Exchange Commission filings, he picked up shares of Aetna, Cigna, Humana, UnitedHealth and WellPoint, among others. All of those companies stand to benefit while Obamacare remains in force; a repeal of the bill could send those shares reeling.

Mr. Bertolini of Aetna insisted on Monday that the deal was not dependent on who wins the White House. But he has to say that. If he believed Mr. Romney was going to win and he still wanted to buy Coventry, he would have waited until after the election and bought it at a sharp discount.

David Fuller's view In freely contested elections, the most affable and charismatic and seemingly generous candidate usually wins. Economic factors and other issues aside, that is what the polls mostly show.

President Obama is a born politician. Former businessman Governor Romney is not a natural politician and it often shows. He has only won a single election and struggled to gain his Party's nomination, despite a well organised and financed primary campaign.

Political forecasting can be a mug's game but I can only imagine Romney winning if a number of Obama-leaning voters abstain this time, due to apathy.