Unrealized capital gains are increases in the value of assets you still own, and under current federal law they are not taxed. The tax only arrives when you sell, exchange, or otherwise dispose of the asset. Because you generally choose when that happens, the timing of a sale is the single most important lever in almost every capital gains planning decision.
What an Unrealized Gain Actually Is
An unrealized gain is the difference between what an asset is worth today and what you paid for it. Buy 100 shares at $50, watch the price climb to $80, and you’re sitting on a $3,000 paper profit. Nothing has changed hands. The market could reverse tomorrow, and the IRS has no claim on that appreciation while you continue to hold.
The number you start from is your cost basis: the purchase price plus costs directly tied to acquiring the asset. For stocks and bonds, that includes commissions and transfer fees. For real estate, it includes closing costs, recording fees, and the cost of improvements with a useful life beyond one year. Basis also decreases over time if you claim depreciation or receive nontaxable distributions.1Internal Revenue Service. Publication 551 (12/2025), Basis of Assets
Tracking basis accurately matters more than most investors realize. Stock splits, reinvested dividends, and property improvements all adjust the number. Get it wrong and you’ll either overpay tax when you sell or underreport a gain and face penalties. Brokerages report basis to the IRS for shares purchased after certain coverage dates, but the burden of proving the correct figure ultimately falls on you.2Internal Revenue Service. Instructions for Schedule D (Form 1040) (2025)
When an Unrealized Gain Becomes Taxable
An unrealized gain turns into a realized gain the moment you sell, exchange, or otherwise dispose of the asset. That transaction fixes a definitive sale price and a specific date, which the IRS uses to calculate the tax. Before that event, the gain fluctuates with the market and carries no tax consequence.3Office of the Law Revision Counsel. 26 USC 1001 – Determination of Amount of and Recognition of Gain or Loss
The underlying principle is the realization doctrine. Income generally isn’t taxable until fixed by a completed transaction. Since you can’t spend an unrealized gain without selling first, it isn’t treated as income. Wages and interest work differently: the IRS taxes those as you receive them.
One important exception to immediate recognition is the like-kind exchange. Under Section 1031 of the Internal Revenue Code, you can swap one piece of investment or business real estate for another of like kind and defer the tax on your gain. Since 2018, this treatment applies only to real property; stocks, bonds, equipment, and other personal property are excluded.4Office of the Law Revision Counsel. 26 US Code 1031 – Exchange of Real Property Held for Productive Use in a Trade or Business or for Investment Real property held primarily for resale doesn’t qualify either.5Internal Revenue Service. Like-Kind Exchanges – Real Estate Tax Tips The gain isn’t forgiven; it’s rolled into the basis of the replacement property, so tax comes due when you eventually sell for cash.
How the Tax Is Calculated Once You Sell
Once you sell at a profit, the rate depends on how long you held the asset. The dividing line is one year.
Short-Term Gains
If you held the asset for one year or less, the gain is short-term and taxed at your ordinary income tax rate. For high earners that can mean a federal rate as steep as 37%. The gain stacks on top of your other income with no preferential treatment.6Internal Revenue Service. Topic No. 409, Capital Gains and Losses
Long-Term Gains
Assets held for more than one year qualify for lower long-term rates of 0%, 15%, or 20%. The rate depends on your taxable income and filing status. For 2026, the thresholds are:7Internal Revenue Service. Revenue Procedure 2025-32
- 0% rate: taxable income up to $49,450 single, $98,900 married filing jointly, or $66,200 head of household.
- 15% rate: income above those amounts but not exceeding $545,500 single, $613,700 married filing jointly, or $579,600 head of household.
- 20% rate: income above the 15% ceiling.
These thresholds are adjusted annually for inflation.
The Net Investment Income Tax
Higher-income taxpayers face an additional 3.8% net investment income tax on capital gains, dividends, and other investment income. The NIIT applies when your modified adjusted gross income exceeds $200,000 single, $250,000 married filing jointly, or $125,000 married filing separately.8Internal Revenue Service. Topic No. 559, Net Investment Income Tax These thresholds are set by statute and are not adjusted for inflation, so more taxpayers cross them each year.
Collectibles
Gains from selling collectibles such as coins, fine art, and precious metals face a maximum federal rate of 28%, regardless of holding period. That’s meaningfully higher than the 20% cap on most other long-term gains.6Internal Revenue Service. Topic No. 409, Capital Gains and Losses
Where You Report It
Realized gains and losses go on Schedule D of Form 1040. Your brokerage sends a Form 1099-B documenting sale proceeds and, for covered shares, cost basis. Keep your own records anyway. The IRS holds you responsible for the correct basis, and any mismatch with the 1099-B will draw a notice.2Internal Revenue Service. Instructions for Schedule D (Form 1040) (2025)
Where Unrealized Gains Typically Sit
Stocks, ETFs, and Mutual Funds
Publicly traded securities are the most familiar source of unrealized gains, since their prices move every trading day. One quirk catches people off guard: mutual funds are required to distribute their realized capital gains to shareholders each year. You owe tax on those distributions even if you reinvested every penny and never sold a share. The reinvested amount does get added to your basis, which reduces your gain when you eventually sell the fund.
Real Estate
Property held for years often carries substantial unrealized gains, especially a primary residence. When you sell your main home you can exclude up to $250,000 of gain from income ($500,000 for married couples filing jointly) as long as you owned and lived in the home for at least two of the five years before the sale.9Office of the Law Revision Counsel. 26 USC 121 – Exclusion of Gain From Sale of Principal Residence Investment properties don’t get this exclusion, though they may qualify for a 1031 exchange to defer the gain.
Cryptocurrency and Digital Assets
The IRS treats digital assets like cryptocurrency as property, not currency. Unrealized gains on crypto are not taxed, and the same short-term and long-term holding rules apply once you sell, trade, or otherwise dispose of the asset.10Internal Revenue Service. Digital Assets Using crypto to buy goods or services is also a realization event, which surprises people who think of it as spending rather than selling.
Collectibles and Tangible Assets
Rare coins, art, antiques, and precious metals all accumulate unrealized gains as they appreciate. The 28% federal ceiling on collectible gains matters when planning a sale, and there is no brokerage feeding basis to the IRS on your behalf, so your own purchase records carry the weight.
The Narrow Cases Where Unrealized Gains Do Get Taxed
The general rule has a few carve-outs. Securities dealers are required under Section 475 of the Internal Revenue Code to “mark to market” their inventory at year-end, meaning they recognize gain or loss as if every security were sold on the last business day of the year. The resulting gain or loss is treated as ordinary income, not capital gain.11Office of the Law Revision Counsel. 26 US Code 475 – Mark to Market Accounting Method for Dealers in Securities Certain non-dealer traders can also elect this treatment.
Legislative proposals to tax unrealized gains more broadly, particularly on ultra-high-net-worth individuals, resurface regularly. As of early 2026, no such federal law has been enacted. The realization requirement remains intact for the vast majority of taxpayers.
Managing Unrealized Gains Before You Sell
Tax-Loss Harvesting
If some holdings have dropped below what you paid, you can sell to realize the loss. Realized losses first offset realized gains dollar for dollar; leftover losses can offset up to $3,000 of ordinary income per year ($1,500 married filing separately). Anything still unused carries forward indefinitely.12Office of the Law Revision Counsel. 26 USC 1211 – Limitation on Capital Losses Watch the wash sale rule: buying the same or a substantially identical security within 30 days before or after the loss sale disallows the loss for that year. The disallowed amount is added to the basis of the replacement shares, so it isn’t gone forever, but the immediate benefit is.
Donating Appreciated Assets
Giving appreciated stock or other capital gain property directly to a qualified charity lets you skip the capital gains tax entirely and deduct the full fair market value. The deduction for appreciated capital gain property donated to a public charity is limited to 30% of your adjusted gross income for the year, with unused amounts carrying forward for up to five additional years.13Internal Revenue Service. Publication 526 (2025), Charitable Contributions This is one of the few paths that permanently eliminates a capital gains liability rather than deferring it.
Timing the Sale
Because you choose when to sell, you can push realizations into lower-income years. Retiring mid-year, taking a sabbatical, or bunching sales into a year when other income is low can land long-term gains inside the 0% bracket. The 2026 zero-rate threshold covers nearly $50,000 of taxable income for a single filer and close to $99,000 for a married couple filing jointly.7Internal Revenue Service. Revenue Procedure 2025-32
What Happens at Death
The most powerful outcome for an unrealized gain is never realizing it. When you die, your heirs receive a stepped-up basis equal to the fair market value of the property on the date of death. All the appreciation that built up during your lifetime is wiped from the tax ledger.14Office of the Law Revision Counsel. 26 USC 1014 – Basis of Property Acquired From a Decedent
Buy stock for $10,000, hold it for decades, die when it’s worth $500,000, and your heirs’ basis becomes $500,000. If they sell immediately, they owe no capital gains tax. Inherited property also automatically qualifies for long-term treatment no matter how quickly they sell after inheriting.
This is why wealthy families sometimes hold highly appreciated assets for life rather than selling. A chain of 1031 exchanges that ends at death can eliminate decades of deferred gains in a single stroke. Whether the step-up survives future tax reform is a recurring question in Washington, but it remains the law for 2026.