FIFO vs. HIFO: How Lot Selection Changes Your Crypto Tax Bill
Sell the same amount of the same asset on the same day, and two people can end up with two different tax bills. The difference isn't the asset, the price, or the amount. It's which specific lot got sold.
Before going further: this post explains how lot selection generally works. It isn't tax advice, and tax rules (especially around crypto) can and do change. Talk to a tax professional about your specific situation before making decisions based on this.
What a "lot" actually is
Every time you buy crypto, that purchase becomes its own record: how much you bought, at what price, and when. That record is a lot. If you've bought Bitcoin five separate times at five different prices, you're not holding one blended position, you're holding five distinct lots, each with its own cost basis.
When you sell, you're not selling "some Bitcoin" in the abstract. You're selling specific lots, and which ones you sell directly changes how much gain or loss you report. The method you use to decide is your lot selection method.
FIFO: first-in, first-out
FIFO sells your oldest lots first. It's the simplest method to reason about: whatever you bought first is treated as sold first, in order, regardless of what you've bought since.
The practical effect: if an asset's price has generally trended up since you started buying, your oldest lots usually have the lowest cost basis. Selling them first tends to realize the largest gain for a given sale.
HIFO: highest-in, first-out
HIFO sells your highest-cost lots first, regardless of when they were bought. For a given sale, this realizes the smallest gain, or the largest loss, out of any lot you're currently holding.
That makes HIFO the method that matters most when the goal is minimizing what you owe on a sale, or maximizing a loss you're deliberately trying to realize, which is exactly what tax-loss harvesting is doing. If you own three lots of the same asset bought at three different prices, HIFO picks whichever one helps your reported outcome the most.
Same sale, different lot, different bill
Say you bought one Bitcoin at $30,000, a second at $50,000, and a third at $65,000. Today it's worth $55,000 and you sell one Bitcoin.
- FIFO sells the $30,000 lot first. You report a $25,000 gain.
- HIFO sells the $65,000 lot first. You report a $10,000 loss.
Same sale, same price, same amount of Bitcoin. The only thing that changed is which lot the sale was attributed to, and it moved the outcome from a $25,000 taxable gain to a $10,000 deductible loss. That's the whole reason lot selection is worth understanding rather than treating as a technical footnote.
Is HIFO always the better choice?
For minimizing what you owe on any individual sale, HIFO wins most of the time by construction. It's not automatically the right call for everyone, though. FIFO is simpler to explain and verify by hand, and some people prefer the consistency of a single, predictable rule applied the same way every time rather than a method that's always hunting for the best-looking lot.
What actually matters more than picking the theoretically optimal method is being consistent and able to show your work. Switching methods sale to sale, or losing track of which lot was used where, is a bigger practical problem than the difference between FIFO and HIFO on any single trade.
Why this is easy to get wrong by hand
A brokerage account tracks lots and cost basis automatically, and usually lets you pick a method from a dropdown. Crypto exchanges generally don't do this kind of tax-aware accounting for you. If you've bought at different times, moved assets between wallets or exchanges, or made more than a handful of trades, reconstructing which lot is which by hand gets tedious and error-prone fast, exactly the kind of task that's easy to get subtly wrong without noticing until tax season.
That gap is a big part of why lot selection stays an afterthought for a lot of crypto holders, even though it can meaningfully change what they owe.
How Rebalance handles this
Rebalance has one account-level setting that governs lot selection for every sell your account makes, whether that's a routine rebalance or a tax-loss harvest. The default is HIFO, since it tends to produce the better tax outcome in most cases, but the setting is yours to change if you'd rather run FIFO across the board.
Whichever method you choose, it's applied consistently and automatically, built directly from your exchange's own trade history, so you're not reconciling lots by hand or wondering after the fact which method was used on a given sale. And like every other action Rebalance takes, you can preview a sell before it executes to see exactly which lot it's about to use and what that means for your reported gain or loss.
See how lot selection fits into the rest of what Rebalance does on the pricing page, or start a 3-day free trial to set your own. A payment method is required to start, but you won't be charged until the trial ends, and you can cancel anytime.