•New methodology for detecting transaction use of crypto in off-chain exchanges.•Demonstrates that large fraction of trades represent international capital movements.•Data covers several hundred million transactions for over 160 countries.•First study to focus on exchanges where roughly 90% of crypto trades take place. This paper employs high frequency transactions data on the world's two oldest and most extensive centralized peer-to-peer Bitcoin markets, enabling trade in the currencies of more than 160 countries. We develop an algorithm that allows us, with high probability, to detect “crypto vehicle transactions” in which crypto currency is used to move capital across borders, and/or to exchange one fiat currency for another. The data suggest that the use of Bitcoin has become an increasingly important channel to receive remittances and evade capital controls in emerging markets. Two event studies on Venezuela and Argentina provide supporting evidence.