Isolation versus economics
Sub-accounts prevent the exchange from netting a long against a short, which is what keeps per-leader results attributable and margin contained. Economically, though, if six leaders are long the same major and one is short it, your portfolio is net long that major.
Both facts are true at once, and confusing them leads to the mistaken belief that isolation is a hedge. It is not a hedge; it is a measurement and containment mechanism.
- Gross exposure: the sum of all position notionals, which drives fees and margin use.
- Net exposure: long minus short, which drives directional sensitivity.
- Market concentration: how much of the net sits in one perp.
- Crowding: how many leaders hold the same view simultaneously.