Why it matters
Margin calls often precede forced liquidation at the worst possible prices.
Operational use: this is how the market taxes urgency. When it appears, slow down or size down.
Common trap
Treating margin calls as negotiable. They aren’t.
Example
Vol spike + slippage pushes equity below requirement; broker demands action.
Operational cue: if you can’t point to it on the chart, in the DOM, or in your broker logs, treat it as a story and trade smaller.
Notes
Design so you never see a margin call.
Quick rule
- If you see this repeatedly, you are in a different regime than your model assumes.
- Regime change usually means position size change.
- When in doubt: trade smaller, or don’t trade.