Very few consumers participating in the Patient Protection and Affordable Care Act exchanges appear interested in the high-premium platinum plans.  

Of the nearly 10 million who have bought insurance through the state marketplaces, only 332,000, or 3 percent, have opted for platinum plans, which have the highest premiums and the lowest deductibles, with insurers typically covering 90 percent of the cost of medical care, compared to 60 percent for the low-premium bronze plans. 

Read: Exchange plan breakdown 

Silver plans, in which insurers typically cover around 70 percent of medical costs, have by far been the most popular type of plan offered on the exchanges. Roughly two-thirds of those who have joined the exchanges have opted for silver plans.  

The small group of consumers who have gone platinum are largely concentrated in a few states. Specifically, 60 percent of platinum buyers are in California, New York, Texas, Florida and Georgia. These states only account for about a third of the overall U.S. population. So how do we explain the overrepresentation of platinum purchasers?  

For starters, all of these states –– particularly New York and California –– are home to affluent populations who are more likely to have the means to pay several hundred dollars a month for insurance. That's what an analysis from Motley Fool, an investment news site, suggests.  

And Florida, which has seen the biggest overall PPACA participation, is also home to an older population, which is more likely to suffer from preexisting conditions and thus find low deductible plans more attractive.  

The good news for platinum buyers is that insurers have not tried to hike platinum rates as dramatically as they have for other types of plans. While insurers have proposed hiking platinum rates by an average of 6 percent in 2016, they proposing upping silver rates by 14 percent, gold plans by 16 percent and bronze plans by 9 percent.  

Six states do not have any platinum plans available on their exchanges.