Exchange vault categories: registered metal is backed by warrants and deliverable now; eligible metal meets the spec but is not currently offered for delivery.
COMEX and LME publish daily vault reports split into these two buckets. Registered inventory is the visible float available to settle shorts; eligible inventory is owner's stock that could be registered if the price made it worthwhile.
Traders watch the ratio because a collapsing registered figure against large short open-interest is the classic setup for a delivery squeeze and a spike in the front-month spread.
Example: if COMEX registered silver is 40 million ounces and December open interest represents 90 million, the market needs eligible metal to convert or longs to roll. Watch the intramarket-spread for the answer.
Original diagrams for the ideas on this page. Illustrative, not real market data.
The bid-ask spread. Buy orders sit below, sell orders above, and the gap between the best bid (50.01) and best ask (50.04) is the spread you pay to cross. Bar length shows the size resting at each price.
Educational only, not advice. Spotted an error? Post in Site Feedback.