Accounting methods · 6 min
FIFO cost basis for crypto
How First-In, First-Out sells your oldest lots first — and why that matters when assets move between exchanges.
First-In, First-Out (FIFO) assumes the oldest remaining purchase lots are sold first. When you move assets between exchanges, FIFO still looks at acquisition timestamps — not which platform currently holds the coin.
Why FIFO matters for multi-exchange traders
Exchange dashboards often calculate gains using only trades on that venue. If you bought on Coinbase and sold on Binance, a single-exchange report may show a misleading gain or missing basis. A portfolio-wide FIFO queue fixes that by tracking lots globally, then applying disposals against the oldest lots available in your unified inventory.
8949 impact
Each disposal can produce one or more Form 8949 lines. When a single sell order consumes multiple lots (because quantity exceeds the oldest lot size), you will see multiple lines with the same sale date but different basis amounts — that is correct.
- Proceeds are allocated per lot based on quantity sold from each lot
- Holding period (short vs long-term) is evaluated per lot acquisition date
- Transferred coins keep the original acquisition date for holding period tests