Tax-loss harvesting

Tax-loss harvesting is a strategy of deliberately selling securities that have declined in value to realize losses, which can offset capital gains elsewhere in the portfolio or offset ordinary income. The investor then immediately reinvests in similar (but not identical) securities to maintain desired exposure, converting unrealized losses into actual tax deductions.

How tax-loss harvesting works

Scenario: An investor holds $10,000 of stock ABC, now worth $7,000 (a $3,000 unrealized loss). Additionally, elsewhere in the portfolio, the investor has a $3,000 capital gain from stock XYZ.

Standard approach: The investor does nothing; the unrealized loss sits; the gain is taxed.

Tax-loss harvesting: The investor:

1. Sells ABC for $7,000, realizing a $3,000 loss.
2. Uses the $3,000 loss to offset the $3,000 gain from XYZ.
3. The net capital gain is $0; no capital-gains tax is owed.
4. Immediately or shortly after, reinvests the $7,000 in a similar (but not identical) security, such as a different stock in the same sector or an ETF tracking a similar index.

The result: the investor retains exposure to the sector or strategy, but has converted a paper loss into a real tax savings.

The wash-sale rule

The IRS prohibits “wash sales” — selling a security at a loss and repurchasing the same or “substantially identical” security within 30 days (before or after). If the wash-sale rule is violated, the loss is disallowed and added back to the cost basis of the repurchased security.

To avoid this:

• Wait more than 30 days before repurchasing the identical security.
• Immediately repurchase a similar (but not identical) security. E.g., sell an S&P 500 index fund and immediately buy a different S&P 500 index fund or a total-US-market fund.

Benefits

1. Tax savings. By converting unrealized losses into deductions, the investor reduces taxes, increasing after-tax wealth.
2. Maintained exposure. By reinvesting in similar securities, the investor keeps desired asset-class or sector exposure without giving it up.
3. No market timing. Unlike the temptation to hold losers hoping they’ll recover, harvesting forced-sells losses and locks in current economics.
4. Annual deduction. Unused losses can be carried forward to future years, providing future tax savings.

Limitations

1. Complexity. Careful tracking of purchase dates and securities is required to avoid wash-sale violations.
2. Limited use if losses exceed gains. If losses exceed gains in a year, only $3,000 of excess loss can offset ordinary income annually. Excess losses carry forward indefinitely but provide deferred, not eliminated, tax savings.
3. Reinvestment risk. The replacement security may perform differently. If you harvest a loss and immediately buy a replacement that rallies, you have converted a real loss into a tax deduction plus an actual loss, not a free improvement.
4. Less valuable in tax-deferred accounts. 401(k)s and IRAs are tax-deferred, so tax-loss harvesting provides no benefit.

Strategic timing

Tax-loss harvesting is most valuable:

• Late in the year. Harvesting in December allows gains from earlier in the year to be offset.
• After market downturns. Bear markets and corrections create abundant loss-harvesting opportunities.
• When rebalancing. Combining rebalancing with loss harvesting kills two birds with one stone.

See also