Last issue I said I'd get into the specific cost basis methods - FIFO, LIFO, HIFO - and what switching between them actually costs you, or saves you, on a real sale. Here's that breakdown.
Most stackers have been buying for years without ever thinking about this. You DCA in, the price moves, you forget about the early buys. Then you sell something and your exchange hands you a tax form using a method you never chose.
That method is FIFO - first in, first out. It sells your oldest coins first. If you've been stacking since 2020 or 2021, those are your cheapest coins. Selling them first means the biggest possible taxable gain on the sale.
But the IRS doesn't require FIFO. It's just the default most exchanges report automatically, because it's the simplest method to calculate. You're allowed to use HIFO - highest in, first out - which sells your most expensive coins first. Same sale, same proceeds, smaller taxable gain.
Here's what that actually looks like with real numbers.
Say you've been stacking since 2021. Your buys ranged from $16,000 a coin during the 2022 lows up to $73,000 near the 2024 peak. Now you need to sell 1 BTC at a price of roughly $97,000.
Under FIFO, your exchange sells your oldest coin first - the one you bought at $16,000. Your taxable gain is $81,000.
Under HIFO, you sell your most expensive coin first - the one you bought at $73,000. Your taxable gain is $24,000.
Same sale. Same $97,000 in proceeds. The difference in taxable gain is $57,000. At a 20% long-term capital gains rate, that's roughly an $11,400 difference in what you owe - on one sale.
That's not a loophole. The IRS allows specific identification of which lots you're selling, as long as you choose a method and apply it consistently. Most people never know they had the choice because their exchange already made it for them.
A few things worth knowing before you sell anything:
You have to elect your method and keep records showing which specific coins (lots) you sold under that method. This usually means tracking purchase dates and prices for every buy, not just relying on your exchange's summary.
You can change methods between tax years, but you have to be consistent within a single tax year for a given asset.
If you've been stacking across multiple exchanges or moved coins between wallets, your cost basis records can get messy fast. This is the part that trips up almost everyone.
I built the tax calculator at satoshitrailblazer.com specifically for this. You can run FIFO, LIFO, and HIFO side by side against your actual buy history and see the real dollar difference before you ever file anything.
You don't need to be planning a sale soon to find this useful. Knowing your numbers now means you're not scrambling in April trying to reconstruct three years of purchases from memory.
Run your own numbers at satoshitrailblazer.com - the tax calculator runs FIFO, LIFO, and HIFO side by side against your real buy history. Free tier gets you started with three tools; full access is $9/month.
— Matt, SatoshiTrails