No your not missing anything mate, you don't even need to register a company for gambling purposes. Its all about your own belief, how you perceive it. If you want to research it, look up "mens rea" and "actus rea" (maybe some variation on spelling) those are the legalities involved with the English court system, if you believe you are doing nothing wrong, you can not be prosecuted.
This is why i am positive this also applies to crypto, the price can move dramatically in a matter of seconds, you are literally gambling on the price swings. :D