This is (possibly what you’re thinking of) a requirement in the EU for CFD trading providers. Providers have to (somewhat prominently) state in all of their ads what percentage of traders loses money using the product.
replyInteresting, would love to see that applied here. Every third ad is about how I can make money on the weather.
replyJust look at lotteries.
replyI don't believe in them because when you consider operational costs, less money comes out of the lottery than goes in, so if everyone simply didn't bet on the lottery, they would have more money than if they bet on it.
But everyone who bets thinks "but what if I win?"