> Just wait until they start killing people to win bets.
Quite likely it has already happened.
There's been an enormous amount of betting on various military strikes by the Trump administration, much of which looks like insider trading.
Almost certainly there have been insiders with money on the line who were financially motivated to launch lethal attacks, which they might have otherwise paused or delayed.
Why almost certainly?
It's much more effective to make the decision first and the bet second.