Leverage isn't a magic word! You're not going to find tradable arb opportunities in forex, full stop. Maybe you don't define arbitrage as a risk free trade exploiting differences in pricing for fully fungible securities? Because that isn't possible for a retail trader, leverage is irrelevant. If you've got your own definition of arbitrage, let everyone know so we're all on the same page. A big hint, you need to understand roll rates if you think the difference in spot and future price represents an arbitrage opportunity.