The only way to stabilize the market is to stop the constant threats of major changes to that market!
This is insurance, it’s not some new or creative enterprise. The instability in the marketplace is a direct response to insurers being told that they’ll either lose business or be hit with no-notice changes that will stop guaranteed payments.
The idiot in the WH is a factor but this is all on the congressional 'pubs - past and present - who have been threatening this fragile ecosystem for the past decade.