Metals options traders working across both LME and CME face a structural challenge that equity and energy traders rarely encounter: the same physical commodity trades on two exchanges with different settlement mechanisms, different lot sizes, different currency conventions, and different delivery specifications. These differences produce a basis — a systematic price differential — that is not constant and cannot be ignored when computing Greeks on a cross-exchange book.
LME Structure: The Three-Month Convention and Prompt Dates
The LME does not trade monthly contracts in the way that CME does. Instead, LME metals have a continuous structure where the reference price is always for delivery in three calendar months. Today's LME copper price is the price for copper delivered three months from today, not for a specific calendar month contract. This creates a rolling forward price that moves every day simply because the delivery date advances by one calendar day.
LME options are typically traded against specific "prompt dates" — Wednesday dates in the nearby three months and then monthly third Wednesdays further out. A March option on LME copper settles against the LME Official Settlement Price on the third Wednesday of March, not against a futures settlement at month-end as CME options do. The difference between Wednesday and month-end settlement introduces timing basis that can be $5–$15 per tonne depending on the shape of the nearby forward curve.
For any desk running options across both LME and CME, the correct delta hedge requires understanding which forward date each option price references. Hedging an LME copper option with CME copper futures introduces basis risk. Allasso maintains separate forward curve models for LME and CME copper and tracks the cross-exchange basis as an explicit risk factor in portfolio Greeks.
Nickel: The Exchange Disruption Case Study
March 2022 offered a dramatic lesson in metals exchange basis risk. LME nickel prices rose 250% in two days when a large short squeeze forced the exchange to halt trading and cancel trades — an unprecedented event in modern commodity markets. During the halt and the subsequent partial trading resumption, CME nickel options continued to trade at different prices than LME nickel.
Traders who held nickel options as hedges against physical positions, or who were running spread trades between LME and CME nickel, faced a complete breakdown in their usual basis relationships. The LME-CME basis, normally stable at $20–$50 per tonne, blew out to hundreds of dollars per tonne during the halt period. Standard basis assumptions in risk systems produced completely wrong delta hedges during this period.
The incident highlighted that exchange basis is a risk factor, not a constant. Nickel provides the most extreme example, but structural differences between exchange mechanisms mean that basis spikes are possible for any base metal during periods of supply disruption, warehouse queue events (a recurring issue for aluminium and zinc at LME warehouses), or exchange operational problems.
Gold Options: Spot, Futures, and OTC Market Fragmentation
Gold options trade in more fragmented markets than base metals. CME COMEX futures options are the most liquid exchange-traded venue. But the OTC market for gold options — primarily through LBMA member banks — trades larger notional volume than COMEX. Additionally, gold spot options (options on spot gold rather than on futures) trade through OTC desks and reference London Fix prices rather than COMEX settlement.
The distinction between gold futures options and gold spot options seems technical but produces different Greeks. A gold futures option is an option on the December COMEX futures price. A gold spot option is an option on the spot price of gold loco London. These two prices differ by the carry cost of gold — the interest rate on gold leased at the LIBOR-equivalent rate — which is normally 0.1–0.5% annualized but can spike to 2–3% during periods when physical gold lending rates tighten.
For a gold options position that spans both futures-based and spot-based option contracts, the portfolio delta must account for the carry cost difference. Allasso handles this by maintaining separate forward models for COMEX gold futures and LBMA gold spot, with the carry cost term explicitly modeled as a time-varying input. When gold lease rates change — as they did significantly in 2020 during COVID central bank interventions — the portfolio Greek recalculates automatically without requiring manual adjustments.
Aluminium: Warehouse Queues and Delivery Optionality
LME aluminium has been subject to warehouse queue problems for over a decade. When a producer delivers aluminium into an LME warehouse to sell on-warrant, the buyer may wait months or years to collect the physical metal if other warrants ahead in the queue are waiting for cancellation. The queue premium — the cost of taking delivery quickly from a warehouse rather than waiting in the queue — has historically ranged from $50 to $250 per tonne above the LME cash price.
For aluminium options traders, this creates a delivery optionality that standard options models ignore. An in-the-money call option on aluminium that delivers into a queue-affected warehouse is worth less than its intrinsic value to a buyer who needs prompt physical delivery. The effective strike is higher by the queue premium. Options that are just out of the money at the screen price might be economically in the money if the queue premium is added to the strike cost.
Allasso tracks LME warehouse queue data for all monitored metals and adjusts aluminium option values to reflect the current queue premium in delivery-adjusted intrinsic value calculations. For desks with physical aluminium delivery obligations, this adjustment can change the exercise decision on near-expiry options by $30–$80 per tonne, which is material on large contract positions.
Currency Risk in Cross-Exchange Metals Options
LME metals prices are quoted in USD per tonne. CME metals prices are also in USD. But the physical metals supply chain introduces currency exposure. Chilean copper is priced in USD but produced with Chilean peso costs. Chinese aluminium smelters have RMB cost bases. South African platinum group metals producers are exposed to ZAR. When the USD strengthens against these currencies, production costs fall in USD terms, which can depress metals prices and affect the directionality of vol moves.
This currency-commodity correlation means that a metals options desk with significant exposure to Chilean copper is not neutral to USD/CLP even if all positions are denominated in USD. A vol model that treats USD-denominated copper prices as the only relevant factor will miss the portion of vol attributable to Chilean peso moves, which accounts for approximately 15-20% of realized copper price vol in normal FX environments.
Allasso includes an optional cross-asset correlation module that tracks currency-commodity correlations for major metals producers. Desks that use this module can decompose their metals option vega into USD commodity vega and FX vega components, which allows more targeted hedging and avoids overstating the effectiveness of commodity-only vol hedges.
Tin and Minor Metals: Pricing Without Liquid Options
For LME tin, cobalt, molybdenum, and other minor metals, liquid exchange-traded options do not exist or trade rarely. Physical producers and consumers who need to hedge price risk use OTC options through commodity banks or structured into swap agreements. Pricing these OTC options requires building implied vol surfaces from sparse broker quotes and historical realized vol data.
The challenge is that historical realized vol for minor metals is not normally distributed — it has fat tails and clustered vol episodes driven by supply disruptions specific to a small number of global producers. Tin, for example, has two dominant producers (Indonesia and Myanmar), and supply disruptions from either affect prices dramatically. A vol model calibrated on LME tin historical data must account for the jump risk embedded in this concentrated supply structure.
Allasso prices minor metals OTC options using a historical simulation approach supplemented by a supply disruption jump model with parameters estimated from the frequency and magnitude of past production disruptions. The result is OTC option prices that embed a meaningful jump risk premium for supply-concentrated commodities, which more accurately reflects the risk that OTC dealers charge for writing options on these markets.