How secure is the marketer’s gas supply?

In the unlikely event of a marketer going out of business, the utility company will make every effort to provide you with natural gas, however the utility has no legal obligation to do so, and any such gas purchases may be at a different price than you have been receiving from your marketer. Are marketers regulated? There is no code in place for marketers, only buy sell brokers who sell to residential and very small commercial users.