First of all, thank you so much for your detailed answer to my post. I really appreciate it.
what's the best way to reach you to discuss?
(I was trying to send you a message, but i'm quite newbie, so can't send it to you)

Some said that as long as I pay the taxes for the amount of (arbitrage) profit that I earned in South Korea, it should be "okay", but not sure.

Hi Guys.

I live in the united states but my citizenship is South Korea.
I've bought some BTC from Gdax, and found that the price in a Korean exchange market is really much higher.
So I've just sold it to the market in Korea, which doesn't impose a tax, and got some arbitrage profit.
After that, I transferred the profit from South Korea to the states and sold it again.

In such case, I'm not sure how to report to IRS. Also, I happened to notice that it could be regarded as "money laundering" but I'd like to ask your thought.

Please share your thought!