When One Account Bleeds the Whole Portfolio: Mapping the Hidden Margin Contagion in Cross-Border Trading
Cross-margining agreements between US brokers and their international counterparties are designed to improve capital efficiency, but they carry a structural risk that most traders never fully examine: a margin breach in a single market can cascade into forced liquidations across entirely unrelated positions worldwide. This investigation traces the mechanics of how margin calls propagate across asset classes and geographies, identifies the broker configurations that amplify contagion risk, and ou