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If been doing some numbers and I don't see the arbitrage. If the price goes up you lose everything (you got margin called).
Am I missing something. Thanks!
As much as I don't encourage people to engage in arbitrage trading (not because it is unprofitable), but it's because the dealer could frown at it, and some of them are even using it as a setup against people. Also, it requires a good amount of money before you can make something good out of it (higher risk).
However, if you must do it, you are doing it wrong by dealing with an exchange. It's better done with multiple dealers whose pricing rates vary. You move the money in and out of them based on the variation and your gain difference calculation, simple.