What Is the London Metal Exchange?
London Metal Exchange (LME) is one of the world’s most influential international commodity exchanges for futures and options contracts. The LME specializes in non-ferrous metals: copper, primary aluminium, lead, zinc, nickel, tin, and aluminium alloy. It also lists the LMEX index contract, which comprises several of these metals. All trades are guaranteed by the London Clearing House. Annual turnover on the LME exceeds USD 4.5 trillion.
The London Metal Exchange was founded in 1877 to ensure reliable supplies of metals imported from abroad. Today, official LME prices serve as benchmarks for long-term contracts between global producers and consumers.
LME official website: www.lme.com
Which Metals Are Traded on the LME?
The London Metal Exchange trades the following base metals:
- Aluminium — traded daily with a total value exceeding USD 12 billion. Its high liquidity makes it the most actively traded metal on the exchange.
- Copper — the second most traded metal, with daily turnover of approximately USD 3 billion.
- Zinc — another core metal, with daily trading volume around USD 4 billion.
- Nickel — traded in relatively smaller volumes, totaling about USD 1 billion per day.
Tin and lead are also traded, but at significantly lower volumes than the four metals above. In 2005, the LME launched trading in plastics.
LME trading volume accounts for roughly 10% of global non-ferrous metal production.
How Does the London Metal Exchange Work?
The LME does not operate continuous price discovery. Instead, trading occurs twice daily during dedicated ring sessions (excluding Saturdays, Sundays, and public holidays). These sessions take place in a large trading hall featuring four curved benches arranged in a ring — each seating ten members or their authorized representatives. This is the iconic ‘ring’ where open-outcry deals are executed. Contracts for different metals are traded sequentially within the same ring.
Each metal is traded for five minutes. Official LME prices — used globally as benchmark references — are set at the close of the morning session. The afternoon session follows the same format, but no official prices are published afterward.
The majority of LME-related transactions occur off-exchange: over 100 brokers trade LME contracts round-the-clock under their own responsibility. Members with offices in other time zones manage metal trading when the London exchange is closed.
Contracts are traded in standardized lots: the minimum lot size is 25 tonnes for all metals except nickel (6 tonnes) and tin (5 tonnes).
What Makes the London Metal Exchange Unique?
The LME is fundamentally a physical market: every contract is backed by deliverable, warehouse-stored metal. Although called ‘futures’, these contracts are designed for actual delivery — not just price speculation. To guarantee physical settlement, the LME maintains extensive global metal inventories across its network of licensed warehouses.
The exchange has developed a rigorous, proprietary system for licensing warehouses, inspecting their facilities, verifying stored metal quality, and ensuring compliance with LME technical standards. This warehouse network reduces logistics costs and streamlines global access to physical metal. Producers simply deliver metal to a nearby LME-approved warehouse and receive a warrant (warehouse receipt), which can be purchased immediately by any major LME broker at the prevailing market price.
The LME and London Clearing House jointly launched the electronic SWORD system. While warehouse companies still issue warrants, they now do so in a standardized electronic format registered in the SWORD database. All issued warrants are held in custody at The First National Bank of Chicago; only electronic versions circulate among market participants.
Only about 2% of all LME contracts result in physical delivery. Those deliveries precisely reflect real-world supply and demand. As a result, changes in LME warehouse stock levels are closely watched and strongly influence price formation.
FAQ
What metals are traded on the LME?
The LME trades aluminium, copper, zinc, nickel, lead, tin, and aluminium alloy — plus an LMEX index contract and plastics since 2005.
How are LME prices determined?
Official LME prices are set during the morning ring session via open outcry; afternoon sessions do not produce official prices.
Is the LME a physical or financial market?
It is primarily a physical market: all contracts are deliverable, backed by metal held in LME-licensed global warehouses.
