Arbitrage across borders is only profitable when the same item has prices that are:

1. Arbitrage depends on a gap the trader can capture. 2. Arbitrage is buying and selling goods or currencies across international borders. 3. It is done at a profit. 4. A profit requires buying lower in one place and selling higher in another. 5. So the same item must carry different prices in each place. _Source: OpenStax Principles of Macroeconomics for AP Courses 2e (CC BY 4.0), Ch 15 'Exchange Rates and International Capital Flows'_