Do stock markets have gambling licenses?
no they have a securities license. Also while a lot of stuff in stock markets are gambling like, the stock market is a positive sum game where very basic techniques (e.g. index investing) have positive expected values.
The buyers and sellers are not the only ones there, there is also the companies injecting money into it via dividends and stock buy backs, I can be a winner on the stock market without there having to be a loser.
No because they're not gabling. They also don't have an alcohol license too.