◇ GLOSSARY
Cross-margin contagion
When cross-margin or shared collateral links positions so stress on one leg drains equity available to others — or when an external insolvency forces sales that hit your mark. Your isolated thesis can fail because someone else's book was cross-margined to the same venue.
Cross margin inside your wallet: a winning ETH long's unrealized profit backs a losing BTC short until it does not. One violent move on either leg shrinks equity for both. Isolated mode contains that damage to the sleeve you posted.
Cross-margin contagion across the market is different but rhymes. Lenders and market makers with cross books must sell what is liquid when they blow up — often BTC and ETH perps — moving mark for every account on the venue.
You cannot see another user's margin mode, but you can see OI and funding extremes. When credit events hit crypto, assume forced cross-venue selling and model your liquidation distance accordingly.