LME Warehouse Queues and Load-Out Rules
Metal sitting in a London Metal Exchange warehouse can get stuck behind a queue of other owners waiting to load it out — sometimes for months or years — and that queue itself becomes a source of price distortion the LME has had to regulate.
Metal deliverable against London Metal Exchange (LME) futures is stored in a network of licensed warehouses. When a trader takes physical delivery, the warehouse must "load out" (physically release) the metal — but warehouses are only required to load out a minimum rate per day. If a warehouse holds far more metal than it loads out, new owners queue up behind everyone who arrived earlier, and load-out queues can stretch to months or even years, even though the metal is sitting right there.
A long load-out queue effectively locks metal in place regardless of who owns it on paper, and because the LME's own settlement price is meant to reflect metal that's actually available, warehouse operators historically had an incentive to let queues grow — it kept rent flowing while trapped metal commanded a premium for the buyers willing to skip the line and buy metal already outside the warehouse.
Worked example
A warehouse holds 1.5 million tonnes of aluminum but is only required to load out 3,000 tonnes per day. At that rate, clearing the existing queue alone would take over a year, even before any new owner joins. A buyer needing physical metal quickly will pay a premium to source aluminum already outside the warehouse system rather than wait in the queue — that premium is a direct, measurable consequence of the load-out rate, not of any actual metal shortage.
After queues at some LME-licensed warehouses stretched past a year during the early 2010s, the exchange tightened its rules, requiring load-out rates to scale up automatically once a warehouse's queue passes a defined threshold, specifically to stop operators from profiting off congestion they had little incentive to fix.
Further reading
- LME, Warehousing Rules and Load-Out Rate Requirements