Margin & liquidation
Margin calls are instant; funding pays on a schedule. The mismatch is where hedged positions die.
The timing mismatch
A delta-neutral pair earns slowly — a fraction of a percent per settlement — and can lose margin fast. Each leg is margined by its own venue in isolation: KuCoin does not know about your Phemex short. A 15% rally is neutral for the pair but, at 3x leverage, moves each leg’s margin balance by 45% in opposite directions. The winning leg’s gain sits unrealized on one exchange while the losing leg’s venue counts down to liquidation on the other.
Funding income cannot save you in that window — it arrives at 8h boundaries; the margin call arrives now.
Leverage on the short leg
The short perp leg deserves the most caution: its adverse direction (up) is unbounded, and violent squeezes are exactly when funding spreads look most attractive to enter. At 2x, liquidation on a short sits roughly 40-50% away depending on the venue’s maintenance margin; at 10x it is within a bad hour for a small cap. In carry structures the spot leg cannot be liquidated at all, which halves the surface — one reason spot-perp carry tolerates leverage worse traders survive.
A liquidation is worse than a loss
When one leg is liquidated the hedge is gone, not just the margin: the surviving leg is an outright position at full size, in a fast market, plus the liquidation fee. The pair strategy has converted itself into the naked directional bet at the worst available entry. If you are not watching, the “safe” spread trade becomes a leveraged single-leg position for hours.
Keeping buffer
- Size from liquidation distance, not margin minimums. Decide the adverse move each leg must survive (say, 30% against the short) and let that set leverage — typically 2-3x, not the venue’s maximum.
- Prefer cross margin for the pair’s legs on each venue, so the whole local balance backs the position — then treat that balance as committed, not idle.
- Pre-plan the rebalance route. Moving collateral between venues takes minutes to hours (withdrawal processing, chain confirmations). A transfer that arrives after the liquidation is a donation.
- Watch marks around volatile hours, not funding times. Liquidation runs on mark price continuously; see Spread moves against you for why the pair’s mark can be deep underwater while the thesis is intact.