If Democrats don't manage to reinstate mandated participation in some other form, and Republicans don't also repeal the subsidies, "on the surface, that would be a great thing for the health insurance business," writes Laszewski.
Decide not to decide: One other possible outcome—though the least likely, most observers seem to think—would be a ruling that the court cannot issue a decision until someone actually pays an unlawful tax, namely the fine for not buying insurance. The IRS is to withhold the penalty from tax refunds starting in 2014.
That could be the most disruptive outcome of all, if only because it opens a whole new chapter of uncertainty surrounding health reform—even after many insurers have spent considerable sums preparing for the new law.
"Of course, the actual policy is important, but what worries the market more a lot of times is just uncertainty," says Morningstar's Davis. He notes that passage of the Affordable Care Act two years ago "was a positive for healthcare funds in general" because after months of acrimonious debate, "the market saw a clear path ahead."