Someone pulled this $400 billion number out of a hat for US sports betting handle years ago. It has little basis in reality after some real analysis has been done.https://twitter.com/BergenBrennan/status/930871926838489089 …
You need to adjust for population. If you look at ratio of sports betting revenue to gaming revenue for NV and apply nationally, you get maybe $1B or so in sports betting revenue (hold, not handle). But still a SWAG. http://craakker.blogspot.com/2015/02/setting-line-for-sports-betting-revenue.html?m=1 …