What is The Cost of Carry Model?
Mathematical Foundation
Laws & Principles
- Spot-Futures Parity: In a perfectly efficient market, the futures price must equal the spot price adjusted for the net cost of carry. If it deviates, arbitrageurs will instantly step in to buy the cheaper asset and sell the more expensive one, forcing the prices back into mathematical parity.
- Contango state (F0 > S0): This occurs naturally when the cost of holding the asset (interest + storage) is higher than the yield it generates. Common in physical commodities like gold and oil during normal supply conditions.
- Backwardation state (F0 < S0): This occurs when the convenience yield (the benefit of physically holding the asset today) is extremely high, usually due to a massive supply shortage or logistical crisis, causing future prices to trade lower than spot.
Step-by-Step Example Walkthrough
" An institutional quantitative trader is analyzing a Gold futures contract expiring in exactly 6 months. They want to check if the current market futures quote of $2,050 is fairly priced or if an arbitrage opportunity exists. "
- Spot Price (S0): Gold currently trades physically at $2,000 per ounce.
- Risk-Free Rate (r): The 6-month Treasury rate is 5.0%.
- Storage Costs (u): Storing/insuring gold costs 1.0% annually.
- Convenience Yield (y): 0% (Since gold generates no yield).
- Cost of Carry: 5.0% + 1.0% = 6.0% continuously compounded over 0.5 Years (6 months).
- Execute Formula: F0 = $2,000 * e^(0.06 * 0.5) = $2,000 * e^(0.03) = $2,060.91.