A tale of two markets! SK Hynix shares skyrocket on the US stock market, while shares in North Korea crash, with a valuation gap between the two reaching $240 billion and a 25% premium!

Can retail investors arbitrage across markets? The answer is: almost impossible.
Large institutions have cross-border channels: stocks bought cheaply in South Korea can be directly bundled through banks and sold as US shares, locking in the spread. But retail investors’ two accounts are isolated, so they can’t move assets over at all.
Retail investors can only look at the spread—the rules that let institutions profit.