SPAN + Exposure Margin & Hedged Portfolio Margin Benefits

Derivatives exchanges do not charge full contract notional value; instead, they charge SPAN (Standard Portfolio Analysis of Risk) Margin plus Exposure Margin. SPAN simulates 16 combinations of underlying price moves and implied volatility shifts to find your portfolio's worst single-day loss.

When you pair a short option with a protective long option (e.g., a Credit Spread or Iron Condor), your maximum loss is mathematically capped—allowing the clearing engine to slash required margin by 50% to 70%.

Hover over key terms below for instant definitions: SPAN Risk Array, Exposure Margin, and Spread Hedge Benefit. For the complete mathematical derivation and edge-case analysis, open naked vs. hedged margin efficiency & ROI math.

• SPAN Risk Array — Sets base margin equal to the worst-case scenario loss across the 16 simulations.
• Exposure Margin — Added on top of SPAN margin to form Total Initial Margin.
• Spread Hedge Benefit — Only granted once the protective leg is actively filled in your account.

1. 1
   Execute Protective Long Wings First

   Buy the OTM hedge legs first so the clearing system sees the protective cap before the short leg arrives.
2. 2
   Execute Short Legs Second

   Sell the inner strikes to immediately receive the hedged SPAN margin rate.
3. 3
   Reverse the Order on Exit

   Always buy back the short legs BEFORE selling the long wings to prevent a naked margin spike.

Implementation & Quantitative Model

1export function sequenceSpreadLegs<T extends { action: "BUY" | "SELL" }>(legs: T[], mode: "ENTRY" | "EXIT"): T[] {2  return [...legs].sort((a, b) => {3    if (mode === "ENTRY") return a.action === "BUY" ? -1 : 1;4    return a.action === "BUY" ? -1 : 1; // On exit, BUY-to-close short legs first!5  });6}

Cross-reference standard risk definitions such as drawdown, slippage, and Sharpe ratio when auditing your logs.