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There are also risks in financial markets that cannot be calculated, and in fact there are quite a lot of them. Just think about the impact of the coronavirus outbreak on the logistics of the world, and the impact of wars and various conflicts between countries. All of this hits the economic situation very hard, which in turn can affect the financial markets.
And do not forget that gambling was invented to have fun and not for every gambler can increase their bankroll in 10 times a year.