DIO — days inventory outstanding
What it measures¶
Days inventory outstanding is how many days, on average, goods sit in stock before they are sold. Inventory is the stock of materials, work in progress and finished goods. The page computes 365 × average inventory ÷ cost of revenue, where the cost of revenue is the direct cost of what was sold.
Why it is on the page¶
It is the second part of the cash conversion cycle: cash spent on stock is locked up until the goods are sold. A rising DIO can mean goods are selling more slowly — James Montier's list of warning flags includes it.
Thresholds, their source and the population they were fitted on¶
The page draws no zones: a bakery turns its stock in days, an aircraft maker in many months.
- Fitted on: no population — a descriptive ratio.
- Evidence grade: not graded.
A worked example¶
Celestica, as the Fundamentals page showed it on 9 August 2026 (fiscal year 2025): DIO 66.1 days — about two months of stock.
What “No verdict” means here¶
The row carries no verdict of its own. It reads not applicable when the company carries no inventory, and insufficient data when inventory or the cost of revenue is not stored.
What the verdict is and is not¶
The figure describes how long goods stayed in stock in one year. It is not a forecast and not an instruction to trade the shares.