FIFO
Matching a disposal against the earliest acquired lots first, oldest before newest.
Updated 2026-07-26
When the same security was bought several times at different prices, something has to decide which purchase the sale is matched against. First-in, first-out takes the oldest lots until the disposed quantity is covered.
It is one convention among several. Others match the most recent lots first, or average all lots together, and different jurisdictions mandate, permit or forbid each of them. The choice changes the computed basis, sometimes substantially.
A calculation labelled FIFO here means exactly that ordering was applied to the lots entered. Whether that ordering is the one your rules require is a question for your rules.
Related terms
2 entries- Cost basis
- What an asset cost to acquire, used as the starting point for computing a gain or a loss on disposal.
- Open market purchase
- An insider buying shares on the market with their own money, reported under transaction code P.
Where this appears in the data
Written for reading the records published here. This is not a legal, tax or accounting definition, and where a jurisdiction defines the term precisely, that definition governs.