™Buying 100 shares at $40 and later 100 at $50 creates separate lots. The chosen identification method can change the basis of a partial sale.
Taxes & Account Rules
Tax lot
A specific group of shares or units acquired in one transaction, with its own acquisition date and basis.
Plain-English context
Put the definition to work.
Identify the actual disposed lot and allowed method; an app's average price may not establish taxable basis.
Further reading and verification. Examples are hypothetical, not current quotes or recommendations. Product terms, tax treatment and market rules can change. IRS Publication 550 — investment income and expenses