Selling a memecoin in chunks: how FIFO splits one sale across several buy lots (record-keeping only)

Not tax advice. All numbers, tokens and signatures below are EXAMPLE data. This guide covers record-keeping only. How any of this is treated where you live is a question for a tax professional.

Most memecoin positions aren't bought or sold in one go. You buy three times as the price runs, then sell a third here and half the rest there. That sale won't line up with any single buy, and a trade log has to decide which buys it used up. Under FIFO (first in, first out), the oldest units go first, and one sale can reach into two or three buy lots.

This guide walks through that matching with real numbers from a spreadsheet, so you can check your own log. It is about record-keeping only.

How the workbook matches sales

In the Nah Crypto Tax Tracker workbook, every trade is a Buy or a Sell row. The workbook sorts the matching by date, then by row order on the same date, across the whole file. Each Sell row gets three figures: proceeds after its fee (column I, Cost/Proceeds), the FIFO cost of the units it used up (column J, Cost basis), and the difference (column K, Realized P/L).

Two details matter for chunked sales:

A buy fee becomes part of that lot's cost. The workbook spreads it over the units of the lot, so a partial sale carries its share of the fee.
A sell fee reduces that sale's proceeds. It isn't spread back onto the buys.

Swaps are logged as two rows: a Sell of what you gave and a Buy of what you got, with the same signature in Tx hash (G). For fees: enter the combined fee once per swap, on the token's row, in fiat, and do it the same way all year. The EXAMPLE below shows only the memecoin rows to keep the arithmetic readable. In a real log, each of these swaps also has its SOL row.

A worked EXAMPLE

Three buys of MEMEX, then three sales of different sizes. All values are EXAMPLE values, in fiat.

Date	Type	Token	Qty	Price	Fee
2025-03-01	Buy	MEMEX	1,000,000	0.0001	0.40
2025-03-05	Buy	MEMEX	500,000	0.0004	0.40
2025-03-20	Buy	MEMEX	500,000	0.0006	0.40
2025-04-02	Sell	MEMEX	600,000	0.0010	0.40
2025-04-10	Sell	MEMEX	800,000	0.0008	0.40
2026-01-15	Sell	MEMEX	600,000	0.0002	0.40

The three lots cost 100.40, 200.40 and 300.40 including their fees.

Sale 1 (600,000). It all comes from lot 1: 60% of 100.40 is a cost of 60.24. Proceeds are 600.00 − 0.40 = 599.60, so realized is +539.36. Lot 1 has 400,000 left.

Sale 2 (800,000). This sale spans two lots: the remaining 400,000 of lot 1 (40.16) plus 400,000 of lot 2 (80% of 200.40 = 160.32). Cost 200.48, proceeds 639.60, realized +439.12. Lot 2 has 100,000 left.

Sale 3 (600,000). Again two lots: the last 100,000 of lot 2 (40.08) plus all of lot 3 (300.40). Cost 340.48, proceeds 119.60, realized −220.88.

We recalculated these rows in the real workbook, and the sheet shows exactly these figures. The per-year Summary reads 978.48 for 2025 (fees 2.00) and −220.88 for 2026 (fees 0.40), with a total of 757.60. The holdings line for MEMEX is 0, and every row in the Check column says OK.

Notice what the sheet does not show: it gives one cost figure per Sell, not a list of lots. If you want the lot breakdown for your own records, write it in Notes (H), e.g. "400k from 2025-03-01, 400k from 2025-03-05".

When a chunk is too big: OVERSOLD

Typos happen most on chunked sales because the quantities are odd. Change sale 3 to 650,000, 50,000 more than you had left. The workbook flags that row OVERSOLD, gives it no cost basis and no realized figure, and Summary's "Rows needing attention" counter goes to 1. The 2026 realized line drops to 0, while its 0.40 fee is still counted, and the MEMEX holdings line shows −50,000.

A negative holding or an OVERSOLD row means a missing Buy or a wrong quantity. Fix the source data rather than the formula.

Same-day chunks

If you buy and sell in pieces on the same day, row order decides the matching. A Sell placed above the Buy it relies on is checked only against Buys above it on that date. See same-day pump.fun flips.

What FIFO here does and doesn't mean

The workbook calculates FIFO only and can't pick specific lots. Which method applies to you is a question for a tax professional; the sheet just keeps the record consistent.

Checklist

One row per buy and per sell chunk, each with its signature in G.
Quantities copied from the explorer, not rounded.
The fee is on the token's row, once per swap.
Column M says OK, and the holdings line matches your wallet.
Optional: the lot breakdown of big sales in Notes (H).

Related guides

A ready-made option

If you'd rather not build this yourself, the Nah Crypto Tax Tracker is an .xlsx plus a PDF guide with plain formulas and no macros: Buy/Sell rows, Tx hash in G, Notes in H, FIFO by date then row order, an OVERSOLD flag and a per-year Summary for 2024 to 2030. FIFO only; not tailored to any country's tax rules. 29 USDC one-time: Nah Crypto Tax Tracker. To get the raw trades first, see exporting Solana DEX history to CSV. Not tax advice.