Realized vs. Unrealized Gain

A realized gain is the profit you lock in when you sell an asset; an unrealized gain (or “paper gain”) is the increase in value of an asset you still own. Only realized gains create a taxable event and incur capital gains tax liability.

The core distinction

The difference is clean: realizing a gain requires a sale or taxable exchange. If you bought a stock for $1,000 and it’s now worth $3,000, you have an unrealized gain of $2,000. That paper profit lives in your portfolio untaxed. The moment you sell it and pocket the cash, that gain becomes realized, and you owe capital gains tax.

This split is foundational to tax planning. You can sit on appreciated assets indefinitely—in your brokerage, your retirement account, your real estate—and owe nothing to the IRS. The government doesn’t tax wealth; it taxes the realization of gain.

Why the distinction matters

Unrealized gains create flexibility. You can manage the timing and magnitude of your tax bills by deciding when—or whether—to sell. A savvy investor might hold winners to defer tax, or sell losers strategically to offset gains elsewhere (a practice called tax-loss harvesting). You might hold concentrated positions for decades, waiting for the right market moment or personal circumstance to crystallize the gain.

Realized gains, by contrast, are final and taxable in the year they occur. You cannot ignore them or defer them indefinitely once the sale is done.

Step-up in basis at death

The tax code creates one famous asymmetry: if you hold an unrealized gain until death, your heirs inherit the asset at its current market value as the new “stepped-up” basis. They owe zero tax on the gain that accumulated while you held it. This is why wealthy individuals often hold appreciated assets for life—the tax is never paid. This dynamic has been a longstanding point of tax-policy debate and subject to recurring legislative proposals.

Holding period and rate tiers

The timing of realization also determines the tax rate you pay. In the US, you benefit from lower long-term capital gains tax rates if you hold an asset for more than one year before sale. Short-term gains (those on assets held one year or less) are taxed as ordinary income at your marginal rate, which can be much higher. This incentive structure encourages longer holding periods and rewards patience.

Tax-deferred accounts blur the line

In retirement accounts like 401(k) plans and IRAs, the distinction softens. Inside these accounts, you can buy and sell freely without triggering taxable events. Realized gains within a traditional 401(k) are not taxable until you withdraw them in retirement. This deferral is a key advantage of these accounts and shifts the tax burden forward in time.

Unrealized losses and wash sales

Just as unrealized gains sit untaxed, unrealized losses sit undeducted. You cannot claim a loss until you realize it by selling. The IRS also restricts “wash sales”—if you sell a security at a loss and buy a substantially identical one within 30 days (before or after), you cannot deduct the loss; instead, the loss is added to your cost basis in the new purchase. This rule prevents investors from harvesting losses for tax benefit while maintaining their economic exposure to the same asset.

Reporting and compliance

Realized gains must be reported on Schedule D (Capital Gains and Losses) and Form 1099-B (Proceeds from Broker and Barter Exchange Transactions). Your broker tracks your cost basis and reports the realized gain or loss when you sell. Unrealized gains are invisible to the IRS unless they materialize into a sale or taxable event.

In recent years, there have been proposals to tax unrealized gains on very high-net-worth individuals, but no such tax currently exists in federal law. The assumption remains: gains are taxed when they are realized.

See also