I got liquidated on June 4 even though my biggest position was a BTC long at 3x. Not because BTC moved too much, but because I had SOL and AVAX perps open on the same account and cross margin meant they all shared one collateral pool. When the wick hit, alts dumped harder than BTC, and the combined drawdown pulled the whole account below maintenance.
The BTC position on its own would have survived easily. A 3x long does not liquidate on a 15% move. That is the part that still annoys me. Cross margin felt safer on paper because unused margin backs every position, but what it really does is let your weakest trade kill the rest.
I started checking how different platforms handle the isolated vs cross choice. Some make you dig through settings before you can switch. BYDFi makes you pick isolated or cross per position before confirming the order. It is one extra click but it would have kept my BTC walled off from the alt liquidation. Not saying that platform is special, just that the UX choice is the kind of guardrail I wish I had hit.
Now I open everything isolated with individual stops. If one trade blows up it takes only that collateral. Cross still makes sense if you are hedging the same pair or running a tight arb, but I will not run a portfolio of volatile alts on shared margin again. Learned it the expensive way.