Tax-Loss Harvesting for DIY Investors

Tax-loss harvesting is the practice of selling investments at a loss to offset capital gains elsewhere in your portfolio. If you have $10,000 in gains from selling one stock and $10,000 in losses from selling another, the losses cancel out the gains, and you owe zero capital gains tax. You can also use up to $3,000 of net capital losses per year to offset ordinary income (like your salary). Excess losses carry forward indefinitely. This strategy turns paper losses into real tax savings while keeping you invested in the market.

Look for harvesting opportunities during market downturns when holdings drop below your purchase price. A 10% market correction might present chances in multiple positions. However, don't wait for crashes. Even modest dips can be worth harvesting if losses exceed transaction costs and effort. Many investors check quarterly or whenever their portfolio drops significantly. Some brokerages now offer automated tax-loss harvesting through robo-advisors, scanning daily for opportunities.

The IRS disallows losses if you buy a "substantially identical" security within 30 days before or after the sale. This 61-day window (30 days before, sale day, 30 days after) is the wash sale period. Violate it, and your loss is disallowed and added to the cost basis of the new shares instead. The rule applies across all your accounts, including IRAs and spouse accounts. You can't sell VTI at a loss in your taxable account and buy VTI in your IRA the same week.

To stay invested while harvesting, buy a similar but not "substantially identical" fund immediately after selling. Common swaps: VTI (Vanguard Total US) for SCHB (Schwab Total US) or ITOT (iShares Total US). VOO (S&P 500) for IVV or SPLG. VEA (Developed International) for SCHF. These track nearly identical indexes but are different enough to avoid wash sale rules. After 31 days, you can swap back if you prefer the original fund. Some investors permanently maintain pairs of equivalent funds for easy swapping.

The value depends on your tax bracket and loss amount. A $10,000 loss that offsets long-term gains saves $1,500 at the 15% rate or $2,000 at the 20% rate. The same loss offsetting ordinary income at the 24% bracket saves $2,400. Across a 30-year investing lifetime with regular harvesting, studies suggest 0.5-1.0% annual return improvement, though this varies. The benefit is largest in early accumulation years when you have high income to offset and decades for savings to compound.

Step 1: Identify positions in taxable accounts trading below your cost basis. Step 2: Calculate the potential tax savings based on your bracket. Step 3: Sell the losing position. Step 4: Immediately buy a replacement fund (not substantially identical). Step 5: Record the trade for tax reporting. Step 6: After 31 days, swap back to the original if desired. Step 7: At tax time, report all sales on Form 8949 and Schedule D. Your brokerage provides the 1099-B with cost basis information.

Don't harvest losses in retirement accounts (IRAs, 401ks) since there's no benefit. Avoid excessive trading costs that exceed tax savings. Watch for wash sales across accounts. Remember that harvesting defers taxes rather than eliminating them (your replacement has a lower cost basis). Don't let tax tail wag the investment dog: never sell a good investment solely for small tax losses. Harvesting works best as an opportunistic add-on to sound investing, not as a primary strategy.