What is Tax-Loss Harvesting and When Does It Make Sense?

Market volatility is not always a risk that must be managed. Market dips create opportunities for tax-loss harvesting. Tax-loss harvesting refers to the strategy of selling underperforming investments in a taxable brokerage account to realize losses, which directly offset taxable capital gains and up to $3,000 of ordinary income.²

By immediately reinvesting the trade proceeds into a non-substantially identical asset, you maintain your desired market allocation while simultaneously building a valuable bank of tax deductions.

When Does Tax-Loss Harvesting Make Sense? (And When It Doesn’t)

The benefits of tax-loss harvesting rely on your individual financial situation. The right time to harvest your losses depends on factors such as your income bracket and long-term wealth strategy.

Scenarios Where Harvesting Delivers Maximum Value

• High Marginal Tax Bracket: High earners subject to the top federal income tax rate (37%), the additional 3.8% Net Investment Income Tax (NIIT), and high state income tax will benefit most dollar-for-dollar from tax-loss harvesting.²
• Significant Realized Capital Gains: Tax-loss harvesting provides investors who have realized substantial taxable gains in the current tax year an immediate dollar-for-dollar offset on those profits.
• Unwinding Low-Basis Concentrated Positions: Investors with large holdings of legacy stocks or executive equity can pair harvested losses with capital gains from selling down these positions. This diversifies wealth without triggering an out-of-pocket tax bill.⁵
• Estate and Legacy Planning: Tax-loss harvesting defers capital gains tax liability. This makes it ideal for assets intended to be transferred to an heir. Because inherited assets receive a step-up in cost basis at death, deferred capital gains are permanently eliminated.⁴

Scenarios Where Tax-Loss Harvesting Does Not Make Sense

• Tax-Advantaged Accounts: Tax-sheltered accounts such as an IRA, 401(k), or Roth account are exempt from annual capital gains taxes. Realizing losses in these accounts yields no tax benefit.²
• Rising Tax Bracket Trajectories: Tax-loss harvesting defers the tax liabilities by lowering the cost basis of replacement securities. If an investor expects to sell these replacement shares when in a significantly higher tax bracket, harvesting can increase their lifetime tax burden.⁴
• Transaction Cross-Drag: Illiquid assets or trading with wide bid-ask spreads can create transaction cross-drag that exceeds the tax value generated.⁵
• Risk of Wash Sales: Reinvesting in identical assets can disallow the loss reduction entirely.⁶

The Wash-Sale Rule Mechanics (IRC §1091)

The wash-sale rule is an IRS regulation (IRC §1091) that disallows a tax loss deduction if you acquire the same or a “substantially identical” security.⁶ This rule prevents investors from claiming a tax deduction while maintaining the same underlying position.

The IRS gives an investor a 61-day calendar window, with 30 days before and 30 days after the trading date. Acquiring a substantially identical security within this timeframe will disallow the tax loss deduction. The IRS evaluates wash sales across all accounts owned by the investor and their spouse, including individual, joint, trust, and retirement accounts.⁶

The IRA Wash-Sale Trap

Selling at a loss in a taxable account and repurchasing within 30 days inside an IRA will permanently disallow the loss deduction in the taxable account. The IRA basis cannot be adjusted; therefore, the tax loss is permanently destroyed.⁷

Unwinding Low-Basis Concentrated Positions

Holding 20%+ of net worth in a single employer stock (RSUs, options) or legacy holdings creates single-company downside exposure.

Pairing harvested losses from your overall volatility against gains from selling down low-basis stock is known as Zero-Cost Diversification.⁵

Example Execution

Selling $100,000 of low-basis concentrated stock ($90,000 gain) shielded by $90,000 of harvested losses elsewhere in the portfolio. This allows for diversification into a balanced bracket with zero out-of-pocket federal tax.²

Tax-Loss Harvesting in Portfolios That Rarely Realize Gains

More passive investors may assume tax-loss harvesting is unnecessary if they rarely realize capital gains. However, tax-loss harvesting can be highly beneficial in passive portfolios for two primary reasons:

1. Realized losses offset up to $3,000 of high-bracket ordinary income annually, yielding an immediate $1,224 tax reduction for investors in top brackets ($3,000 x 40.8%).²
2. Unused capital losses can fund a Tax Loss Bank. Unused capital losses carry forward indefinitely on Schedule D to shelter unexpected future liquidity needs.²

Coordinating tax loss carryforwards requires a close alignment between wealth advisors and tax preparers. More information on the structure of these advisory responsibilities is available here.

Managing Transaction Cross-Drag

While tax-loss harvesting creates tax savings, trading activity naturally erodes net returns through transaction cross-drag. Transaction cross-drag is often seen in the form of:

• Bid-Ask Spreads: Trading illiquid or highly volatile assets may present unfavorable execution prices.
• Execution Lag: Delays between liquidating an asset and buying replacements may cause an investor to miss market rallies.
• Involuntary Gain Realization: Selling an entire asset lot to harvest a loss may inadvertently trigger additional capital gains if part of the lot has unrealized appreciation.

To ensure your tax savings comfortably exceed the costs of transaction cross-drag, establish minimum loss hurdles. A common rule of thumb is to harvest only when a tax lot has an unrealized loss exceeding 4-5% of its value, or $5,000 or more in total loss value.⁵

Direct Indexing: The Scaled Version of Tax-Loss Harvesting

Scaling up tax-loss harvesting leads to direct indexing. Direct indexing is when you hold individual stock constituents of an index in a separately managed account (SMA) rather than a single index ETF.⁸

Even when an overall index, such as the S&P 500, rises +15% in a year, roughly 150 to 200 individual stock constituents within the index decline.⁸

Direct indexing enables continuous harvesting of individual underperforming equities, generating an estimated 0.50% to 2.00% in annual tax alpha for high-bracket investors.⁸

Integrating Tax-Loss Harvesting in Your Wealth Plan

To get the most out of tax-loss harvesting, integrate the practice into a comprehensive, long-term wealth strategy.

If you hold substantial pre-tax retirement accounts alongside taxable brokerage assets, coordinate loss harvesting with tax-bracket management, such as evaluating multi-year Roth conversions.

References

1. Vanguard Group. Tax-Loss Harvesting Explained: Offset Gains and Reduce Taxes. Vanguard Investor Resources, 2026. https://investor.vanguard.com/investor-resources-education/taxes/offset-gains-loss-harvesting
2. Internal Revenue Service (IRS). Publication 550: Investment Income and Expenses. U.S. Department of the Treasury, 2026. https://www.irs.gov/publications/p550
3. Charles Schwab. Tax-Efficient Investing: Strategies & Direct Indexing Benefits. Schwab Brokerage, 2026. https://www.schwab.com/invest-with-us/tax-efficient-investing
4. Kitces, Michael. Tax-Loss Harvesting vs. Tax-Gain Harvesting Trajectory Analysis. Nerd's Eye View, Kitces.com, April 19, 2023. https://www.kitces.com/blog/forget-harvesting-losses-its-time-to-harvest-gains/
5. Greenspring Advisors. Tax-Loss Harvesting Strategy: Benefits, Limitations, and Key Use Cases for High-Net-Worth Portfolios. Greenspring Insights, November 14, 2024. https://greenspringadvisors.com/insight/tax-loss-harvesting/
6. Internal Revenue Code § 1091: Loss from Wash Sales of Stock or Securities. Legal Information Institute, Cornell Law School, 2026. https://www.law.cornell.edu/uscode/text/26/1091
7. Internal Revenue Service (IRS). Revenue Ruling 2008-5: Restricting Wash Sales Across Retirement and IRA Accounts. Internal Revenue Bulletin 2008-3, January 22, 2008. https://www.irs.gov/irb/2008-03_IRB
8. Parametric Portfolio Associates (Morgan Stanley). What Is Direct Indexing? Unlocking Tax Alpha Through Custom SMA Portfolios. Parametric Insights, October 12, 2025. https://www.parametricportfolio.com/blog/direct-indexing