Tax-loss harvesting gets pitched in robo-advisor marketing as a near-magical way to boost after-tax returns. The reality is more modest: it’s a real tool that helps in specific situations and saves nothing — or actually costs money — in others. Here’s what’s actually happening when you “harvest losses,” and the situations where it’s worth your time.
This piece is educational and not personal tax or investment advice. Tax rules change frequently and depend on your specific circumstances. Verify with a tax professional or current IRS guidance before acting.
What tax-loss harvesting actually is
When a security in your taxable brokerage account drops below your purchase price, you have an “unrealized” capital loss. That loss only counts on your tax return if you sell — at which point it becomes “realized.”
Tax-loss harvesting means deliberately selling a position at a loss to capture that realized loss for tax purposes, then reinvesting the proceeds into something similar so you stay in the market.
The realized loss does two things:
- Offsets realized capital gains in the same tax year, dollar for dollar
- If losses exceed gains, up to $3,000 of net loss can offset ordinary income; remaining loss “carries forward” to future tax years
It only matters in taxable accounts. In a Roth IRA, traditional IRA, or 401(k), there are no capital gains taxes, so harvesting is meaningless.
The wash-sale rule
The IRS wash-sale rule says: if you sell a security at a loss and buy “substantially identical” securities within 30 days before or after the sale, the loss is disallowed for tax purposes.
Practical implications:
- You cannot sell VTI at a loss on Monday and buy VTI back on Thursday. The loss is disallowed.
- You can sell VTI and buy a similar-but-not-identical fund (e.g., ITOT — also broad US market). The IRS has not formally defined “substantially identical” for funds with different sponsors and underlying indexes, but most tax practitioners treat funds tracking the same index as risky and funds tracking different broad indexes as safe.
- The 30-day window includes purchases in your IRA and your spouse’s accounts. This catches a lot of inadvertent wash sales.
- If you have automatic dividend reinvestment turned on, that reinvestment can trigger a wash sale. Turn it off in the 30 days before/after harvesting.
How much does harvesting actually save?
The marketing math goes: “Harvest a $3,000 loss, save up to $1,000 in taxes.” That’s the upper bound, only true if:
- You’re in the 32% federal bracket plus state taxes
- You actually have $3,000 of net realized losses
- You don’t have offsetting gains that absorb the losses
The realistic median for a typical retail investor in a $50K–$200K taxable account in 2026 is roughly $50–$300 per year in tax savings from harvesting. Not zero, but not the “thousands of dollars” some marketing implies.
The savings are also a tax deferral, not a tax elimination. When you sell the replacement security later, your cost basis is the lower harvested-share basis (or the new replacement’s purchase basis, depending on how the wash sale resolved), so future capital gains are larger by roughly the same amount. The economic value is the time-value of the deferred tax — meaningful over decades, modest over a few years.
When harvesting is genuinely worth it
You have realized capital gains in the same year. If you sold a position for a $15,000 gain, harvesting $15,000 of losses fully cancels that gain. This is the single highest-value harvesting scenario.
You’re in a high tax bracket and have meaningful taxable balances. Above $100K in taxable accounts and a 24%+ marginal bracket, harvesting starts to compound meaningfully over years.
You have a large unrealized loss in a position you’d hold anyway. Selling, harvesting, and re-buying a similar fund maintains your market exposure while capturing the loss.
A robo-advisor or tax-aware fund does it automatically. Wealthfront, Betterment, and several institutional tax-aware funds harvest losses across many small lots throughout the year. The frictional cost is near zero, so even modest savings are pure gain.
Your investment thesis on the position has changed. If you’d sell anyway, doing it during a down period to claim the loss is free money.
When harvesting is not worth it
Small balances or gain-free years. If you don’t have realized gains and don’t earn meaningfully more than the $3,000 ordinary-income offset cap, the savings are small and don’t justify the operational complexity.
You’d inadvertently trigger wash sales. With dividend reinvestment, recurring buys, or spouse account purchases, accidental wash sales can wipe out the harvested losses. If you can’t reliably control all purchases in the 30-day windows, harvesting is fragile.
You’d switch into a worse fund permanently. If your replacement fund has higher expenses, less tax efficiency, or worse tracking, the loss savings can be eaten by ongoing performance drag. The fund you swap into needs to be at least as good as the one you sold.
Short-term loss / long-term gain mismatches. Short-term losses first offset short-term gains, which are taxed as ordinary income. Long-term losses first offset long-term gains, which are taxed at preferential rates. The “value” of a harvested loss depends on which type it is, and on what gains you have to offset.
You’re already in a low or zero capital gains bracket. If your taxable income puts you in the 0% long-term capital gains bracket (single filers under ~$48K in 2026, varies), harvesting losses to offset gains taxed at 0% saves nothing.
A practical workflow if you’re going to do it
- Once a year (e.g., late November or December): review taxable holdings for unrealized losses. Most brokerages show this on the positions tab.
- Identify replacement candidates before selling. For VTI: ITOT or SCHB are commonly used. For VOO: SPLG or IVV. For VXUS: IXUS. Ensure the replacement isn’t substantially identical and is acceptable as a long-term hold.
- Disable automatic dividend reinvestment on the harvested security and its replacement for at least 30 days before and 30 days after.
- Check IRA accounts (yours and spouse’s) for the same security — purchases there can trigger a wash sale.
- Sell the loss and immediately buy the replacement. Same-day execution maintains market exposure with minimal slippage.
- Track the replacement’s cost basis carefully. When you eventually sell, the basis matters for the capital-gains calculation.
- Hold replacements at least 31 days before swapping back, if you want to return to the original security. Otherwise the round-trip can create a wash sale on the original loss.
The robo-advisor question
Wealthfront and Betterment offer tax-loss harvesting as a flagship feature. Both do it well, automatically, across many small lots — exactly the situation where harvesting compounds best.
The trade-off: the AUM fee (typically 0.25%) is paid every year on the entire balance, while harvesting savings are typically 0.1%–0.4% in a good year. In years with no losses to harvest (steady markets), the fee outweighs the savings.
For most readers with a long-term Bogleheads-style portfolio at Vanguard, Fidelity, or Schwab and modest taxable balances, manual once-yearly harvesting is fine. For larger taxable balances ($300K+) where automated daily harvesting can run continuously across many small lots, the robo fee is more defensible.
Common mistakes
Harvesting just because the position is down. If your investment thesis is intact and there are no gains to offset, the savings may not justify the trade.
Triggering a wash sale via 401(k) or IRA contributions. A regular paycheck contribution that includes the harvested security on autopilot disqualifies the loss.
Selling a tax-efficient fund into a less tax-efficient fund. The replacement needs to be similarly tax-efficient. Index ETFs are typically more tax-efficient than mutual funds.
Forgetting that the loss carries forward. If you have $20,000 of unused harvested losses, those reduce your future capital gains tax bill by the same amount. Track carryforwards on Schedule D.
Counting the same dollar twice. A harvested loss saves taxes today but lowers your cost basis on the replacement, increasing future capital gains. The net is the time value of the deferral, not the full headline number.
Bottom line
Tax-loss harvesting is a legitimate, modest tool. For investors with realized gains to offset or large taxable balances and tax-aware automation, it’s worth doing. For most retail investors with steady-state index portfolios in tax-advantaged accounts plus a small taxable balance, the savings are real but small enough that simplicity often beats complexity.
FAQ
Can I harvest losses every year?
In principle yes, but losses don’t always exist. In rising markets, your positions may have no unrealized losses to harvest. The first year of a new contribution or after a market dip is typically the highest-value harvesting year.
What about cryptocurrency?
The wash-sale rule, as of 2026, technically applies only to “securities,” and cryptocurrency is treated as property by the IRS rather than a security. This means you can sell crypto at a loss and immediately repurchase without wash-sale disallowance. Legislation has been proposed to extend wash-sale rules to crypto; verify current status before relying on this.
Does the loss need to be long-term to be useful?
Both short-term and long-term capital losses are useful, but they’re applied differently. Short-term losses first offset short-term gains (taxed at ordinary rates), then long-term gains. Long-term losses first offset long-term gains, then short-term gains. The order matters for the amount of tax saved.
Can I deduct losses from selling my home?
Personal residences and personal-use property cannot generate deductible losses for federal income tax. Tax-loss harvesting applies to investment securities only — stocks, bonds, ETFs, mutual funds — held in taxable accounts.