Horizon Blue Cross Blue Shield, New Jersey's largest health insurer, has filed to become a publicly held for-profit company. The move could bring the state a $1 billion windfall for healthcare, but it comes with concerns about how the change could impact consumers. Horizon representatives said converting to a for-profit company would help raise capital and allow competition with other insurers. The value of the insurer on the open market, which is estimated to be at least $1 billion, would go to a charitable foundation that, under current state law, would aim to provide healthcare for the needy. Horizon covers 3.6 million people, roughly four out of every 10 New Jerseyans.