COMEX is the main gold futures exchange in the United States (based in New York). Gold futures contracts are promises to buy or sell gold at a set price in the future.
COMEX Inventories is the amount of physical gold sitting in COMEX-approved warehouses — gold that can actually be delivered to settle futures contracts. When inventories fall, it means less gold is physically available at COMEX.
How does it affect gold?
When COMEX inventories fall, there's less gold available to deliver to buyers who want the physical metal. Tight supply → sellers have more pricing power → gold price tends to rise.
When inventories rise, supply is ample and price pressure eases.
Decreasing COMEX inventories can also signal that gold is moving to Asia or Europe, where demand is higher — a sign of global demand strength.