A poll by the Kaiser Family Foundation found that 61 percent of people enrolled in marketplace plans are satisfied with their insurance choices, but 53 percent think the market is collapsing.

A deal or joint venture between Humana and Walmart might help defend against competitive threats in both the retail and health care industries.

Because the new plans will not be defined as "health insurance," they will not be subject to a variety of state and federal insurance regulations. Or so proponents hope.

Markets have been roiled by worries over talk of a potential trade war and a sell-off in tech stocks.