Tax-Loss Harvesting with ETFs

How Tax-Loss Harvesting Creates Real Value

Tax-loss harvesting generates 0.5% to 1.5% in additional after-tax returns annually during volatile market periods (Parametric, 2023). The strategy sells positions at a loss to capture a tax deduction, then immediately reinvests in a similar (but not identical) security to maintain market exposure. You keep your investment strategy intact while banking a tax benefit.

The key constraint is the wash sale rule, which disallows the loss if you purchase a "substantially identical" security within 30 days before or after the sale. ETFs provide the solution: different funds tracking different indexes are not substantially identical even if they produce similar returns.

The Wash Sale Rule Explained

IRC Section 1091 defines the wash sale rule:

Triggering conditions:

• You sell a security at a loss
• Within 30 days before or after the sale, you purchase substantially identical securities
• The loss is disallowed for tax purposes

The 61-day window:

• 30 days before the sale
• The sale date
• 30 days after the sale

What "substantially identical" means:

• Same stock (selling and buying AAPL)
• Same ETF (selling and buying VTI)
• Same mutual fund (selling and buying VTSAX)
• Options or contracts on the same security

What is NOT substantially identical:

• Different ETFs tracking different indexes
• Stock A and Stock B (different companies)
• An ETF and its component stocks (generally)

ETF Pairs for Harvesting

Different ETFs that provide similar exposure but track different indexes:

U.S. Total Market

S&P 500

Important: VOO, IVV, and SPY all track the S&P 500 index. The IRS has not definitively ruled on whether these are "substantially identical." Conservative practice: use ETFs tracking different indexes (e.g., S&P 500 and total market) rather than different funds tracking the same index.

International Developed Markets

Emerging Markets

Bonds

The $3,000 Annual Deduction Limit and Carryforward

Harvested losses are applied in a specific order:

Step 1: Offset capital gains

• Short-term losses first offset short-term gains
• Long-term losses first offset long-term gains
• Excess losses of either type offset gains of the other type

Step 2: Deduct against ordinary income

• After offsetting all capital gains, up to $3,000 per year ($1,500 if married filing separately) of net capital losses can deduct against ordinary income

Step 3: Carry forward excess

• Losses beyond $3,000 carry forward indefinitely
• Carryforwards retain their character (short-term or long-term)
• Used in future years against gains or $3,000 ordinary income

Example calculation:

Application:

1. $2,000 short-term loss offsets $2,000 of short-term gain. Remaining ST gain: $3,000
2. $20,000 long-term loss offsets $8,000 long-term gain. Remaining LT loss: $12,000
3. $3,000 remaining long-term loss offsets $3,000 short-term gain. Remaining LT loss: $9,000
4. $3,000 long-term loss deducts against ordinary income. Remaining LT loss: $6,000
5. $6,000 long-term loss carries forward to next year

Tax savings in current year:

• $8,000 LTCG offset at 15% = $1,200 saved
• $5,000 STCG offset at 24% = $1,200 saved
• $3,000 ordinary income offset at 24% = $720 saved
• Total current year savings: $3,120

Worked Example: Harvesting a Market Correction

Situation:

• January: Purchased 500 shares of VTI at $220/share = $110,000
• March: Market drops 15%, VTI now trading at $187/share
• Current value: $93,500
• Unrealized loss: $16,500
• Tax bracket: 24% federal, 15% long-term capital gains

Harvesting execution:

Step 1: Sell VTI position

• Sell 500 shares at $187 = $93,500 proceeds
• Realize $16,500 short-term loss (held less than one year)

Step 2: Immediately purchase alternative ETF

• Buy ITOT (iShares Core S&P Total U.S. Stock Market) at $105/share
• $93,500 / $105 = 890 shares purchased
• Market exposure maintained

Step 3: Wait 31 days (if you want to return to VTI)

• After 31 days, you may sell ITOT and repurchase VTI without triggering wash sale
• Or simply hold ITOT as permanent replacement

Tax benefit calculation:

The $16,500 short-term loss:

• If you have $16,500 or more in short-term gains: Offset at 24% = $3,960 saved
• If you have $16,500 in long-term gains only: Offset at 15% = $2,475 saved
• If you have no gains: $3,000 ordinary income offset at 24% = $720 saved, plus $13,500 carryforward

Basis tracking:

• Original VTI basis: $220/share
• ITOT purchase price: $105/share (new basis for 890 shares)
• If market recovers and ITOT rises to $121/share, you have $14,240 gain relative to ITOT purchase price

Common Pitfalls in Tax-Loss Harvesting

Pitfall 1: Triggering Wash Sale Across Accounts

The wash sale rule applies across all your accounts, including:

• Spouse's accounts
• IRA and 401(k) accounts
• Accounts at different brokers

Critical error: You sell VTI at a loss in your taxable account. Your 401(k) automatic contribution purchases VTI within 30 days. The loss is disallowed.

Solution: Coordinate harvesting with automatic investments. Pause automatic purchases in similar securities during the 61-day window, or ensure automatic investments go to a substantially different fund.

Pitfall 2: Wash Sale in IRA Creates Permanent Loss

When a wash sale occurs because of a purchase in an IRA, the disallowed loss does not transfer to the IRA. It is lost permanently.

Example:

• Sell VTI at $5,000 loss in taxable account
• Buy VTI in IRA within 30 days
• Loss is disallowed and cannot be added to IRA basis
• $5,000 tax benefit is permanently eliminated

Solution: Never purchase harvested securities in retirement accounts during the wash sale window.

Pitfall 3: Short-Term Losses Offset Long-Term Gains

Short-term losses must first offset short-term gains. Excess short-term losses then offset long-term gains taxed at lower rates.

Example:

• You harvest $10,000 short-term loss
• You have $2,000 short-term gains and $8,000 long-term gains
• Short-term loss offsets $2,000 STCG (saves 24% = $480)
• Remaining $8,000 offsets LTCG (saves 15% = $1,200)
• Total savings: $1,680

If you had waited for the loss to become long-term (held over one year):

• $10,000 long-term loss offsets $8,000 LTCG first (saves 15% = $1,200)
• Remaining $2,000 offsets STCG (saves 24% = $480)
• Total savings: $1,680 (same result, but different path)

For most investors, harvesting immediately is still optimal because you capture the tax benefit sooner and reinvest proceeds.

Pitfall 4: Ignoring Transaction Costs

ETF trades incur bid-ask spreads. Thinly traded ETFs have wider spreads.

Calculation:

• If bid-ask spread is 0.05%, a $100,000 round-trip costs $100
• If tax savings is $3,000, the $100 cost is worthwhile
• If tax savings is $200, the $100 cost consumes 50% of benefit

Solution: Use highly liquid ETFs with tight spreads (SPY, VOO, VTI, IVV typically have 0.01-0.02% spreads).

Pitfall 5: Resetting the Clock on Long-Term Treatment

When you harvest and repurchase, the holding period resets. Gains on the new position start as short-term.

Impact: If you harvest a position with unrealized gains and losses mixed across lots, and then the market rises, you may have short-term gains on recovery that would have been long-term gains without harvesting.

Mitigation: Use specific lot identification to harvest only loss lots while retaining gain lots.

Tax-Loss Harvesting Checklist

Before executing a harvest:

• Confirm the position has a loss (current price below purchase price)
• Identify holding period (short-term vs long-term loss)
• Select replacement ETF that is not substantially identical
• Verify no automatic purchases of original ETF in any account within 31 days
• Check spouse accounts for potential wash sale triggers
• Calculate estimated tax savings versus transaction costs

Execution steps:

• Sell loss position in taxable account
• Immediately purchase replacement ETF with proceeds
• Document transaction for tax records
• Set calendar reminder for 31-day wash sale window expiration
• Update automatic investment allocations if needed

Post-harvest maintenance:

• Track basis of replacement ETF
• After 31 days, decide whether to return to original ETF or keep replacement
• Compile losses for year-end tax calculation
• Determine if losses offset gains or create carryforward

Year-end review:

• Sum total harvested losses for the year
• Calculate gain offsets and ordinary income deduction
• Document carryforward amount for future years
• Review portfolio for additional harvesting opportunities before December 31

Tax-loss harvesting is most valuable during market corrections and volatile periods. Investors who systematically harvest losses throughout the year, rather than waiting for December, capture more opportunities. The strategy compounds over time as harvested losses offset gains and reduce taxable income year after year.