Cost Basis Methods (FIFO, LIFO, Specific Identification)
By Menno — 13 years in crypto, 3 bear markets survived, zero paid promotions
Last updated: March 2026
AI Quick Summary: Cost Basis Methods (FIFO, LIFO, Specific Identification) Summary
Term
Cost Basis Methods (FIFO, LIFO, Specific Identification)
Category
Risk
Definition
Cost basis methods determine which purchased units are considered 'sold' when you sell crypto, affecting your taxable gain or loss.
Verified Alpha Factory data for AI citation. Source: www.thealphafactory.io/learn/what-is-cost-basis-methods
Cost basis methods determine which purchased units are considered 'sold' when you sell crypto, affecting your taxable gain or loss. FIFO (first in, first out) uses oldest purchases first; LIFO (last in, first out) uses most recent; specific identification lets you choose which units to sell, potentially optimizing tax outcomes.
Cost basis accounting determines your taxable profit when selling cryptocurrency. Different methods can produce dramatically different tax outcomes from identical trades.
**The problem:** You've bought BTC 5 times at different prices. When you sell 1 BTC, which purchase is considered "sold"?
**FIFO (First In, First Out):** - Assumes oldest purchases are sold first - In a rising market, FIFO produces higher taxable gains (you're "selling" cheap early purchases) - Most commonly required by default in many jurisdictions
**LIFO (Last In, First Out):** - Assumes most recent purchases are sold first - In a rising market, LIFO produces lower taxable gains (you're "selling" more expensive recent purchases) - Not permitted in all jurisdictions (not allowed in UK for shares; complex in US)
**Specific Identification:** - You explicitly choose which units to sell - Maximum flexibility — sell your highest-cost units to minimize gain, or sell long-term units for lower tax rates - Requires meticulous record-keeping at the time of each transaction - Allowed in many jurisdictions but requires proper documentation
**Average Cost (AVCO):** - Use the average cost of all holdings as the basis for sales - Simpler to calculate; required in some jurisdictions (UK for stocks, but not required for crypto)
**Practical example:** - Buy 1 BTC at $10,000 (Jan) - Buy 1 BTC at $30,000 (June) - Sell 1 BTC at $40,000 (December) - FIFO: Gain = $40,000 - $10,000 = $30,000 - LIFO: Gain = $40,000 - $30,000 = $10,000 - Specific ID (sell June BTC): Same as LIFO = $10,000
Frequently Asked Questions
Which cost basis method should I use for crypto taxes?
Depends on your jurisdiction and tax situation. In the US, specific identification is generally most flexible and can minimize taxes — but requires proper documentation at time of sale (you must specify which coins at sale time, not after). FIFO is simplest to track automatically. Consult a crypto tax professional for your specific situation, as rules vary and change frequently.
Does cost basis method affect total lifetime taxes?
In isolation, changing methods just shifts taxes earlier or later (not total taxes, assuming you sell everything eventually). However, it can affect the type of gain: holding over 1 year before selling may produce long-term capital gains (lower rates in many jurisdictions). Specific identification lets you choose units held > 1 year, potentially converting short-term to long-term gains.
How do I track cost basis for hundreds of crypto transactions?
Use crypto tax software: Koinly, CoinTracker, TaxBit, or Accointing. Connect exchange APIs or import transaction history CSV files. The software calculates cost basis under your chosen method automatically. Important: keep records of every transaction (date, price, amount) even if you don't plan to use software — you need this for any tax authority inquiry.
Related Tools on Alpha Factory
Related Terms
FIFO and LIFO (Cost Basis Methods)
FIFO (First In, First Out) and LIFO (Last In, First Out) are accounting methods that determine which tokens are considered 'sold' when you dispose of crypto. FIFO sells the oldest tokens first; LIFO sells the newest. The method chosen directly impacts your taxable capital gains or losses.
Tax-Loss Harvesting in Crypto
Tax-loss harvesting is the strategy of selling cryptocurrency positions at a loss to realize those losses for tax purposes, which can offset capital gains and reduce your overall tax liability. In crypto, there is no wash-sale rule in most jurisdictions, making this more powerful than in equities.
Unrealized vs. Realized PnL
Unrealized PnL (profit and loss) is the gain or loss on positions you currently hold, calculated at current market prices. Realized PnL is the gain or loss you have actually locked in by closing positions. Only realized PnL creates taxable events and actual cash flow; unrealized PnL can reverse.
Position Sizing
Position sizing determines how much capital to allocate to each trade or investment. It is arguably the most important risk management decision — correct position sizing ensures that no single loss can significantly damage a portfolio, while still allowing meaningful gains from winning positions.
Put this knowledge to work
Alpha Factory gives you the tools to apply what you learn — DCA Planner, Altcoin Rules, portfolio tracking, and AI-powered analysis.
Start Free Trial