There is a professional gambler in Australia[0] who has the betting companies _compete_ for his business and offer him rebates on volume. His firm is double-digit percentage of the Australian betting market and employs ~hundreds of professional traders, developers etc. (it operates no diff to a hedge fund).

As an aside - it was his firm that was responsible for the recent "breaking" of the Texas lottery[1]

[0] https://en.wikipedia.org/wiki/Zeljko_Ranogajec

[1] https://www.houstonchronicle.com/news/investigations/article...