How do taxes change asset allocation and rebalancing decisions?

Taxes fundamentally alter the asset allocation problem. Here's a structured breakdown: **1. Asset Location (Where to Hold What)** Taxable investors have both taxable accounts and tax-advantaged accounts (IRAs, 401(k)s). The principle of *asset location* says: - **Tax-advantaged accounts:** Hold tax-inefficient assets — taxable bonds (interest taxed at ordinary rates), REITs (distributions taxed at ordinary rates), actively traded strategies (frequent short-term gains) - **Taxable accounts:** Hold tax-efficient assets — broad equity index funds (low turnover, qualified dividends, long-term capital gains), municipal bonds (tax-exempt interest), tax-managed strategies **Example:** If your target is 60% equities / 40% bonds and you have $500K in a 401(k) and $500K in a brokerage account: - 401(k): $400K bonds + $100K equities ($500K total) - Brokerage: $500K equities - Combined: $600K equities (60%) + $400K bonds (40%) ✓ Same target allocation, but the tax drag is minimized because bond interest isn't taxed annually in the 401(k). **2. After-Tax Return Adjustments** When building CMEs for a taxable investor, you need after-tax expected returns: - Bonds: r_after-tax = r × (1 − t_income) - Equities: r_after-tax ≈ (dividend yield × (1 − t_div)) + (capital gain return × (1 − t_cg × turnover)) This typically shifts the optimal allocation *toward* equities and *away from* bonds for taxable investors (since equities are taxed more favorably). **3. Rebalancing With Taxes** Taxes create a significant friction for rebalancing because selling appreciated positions triggers capital gains taxes. **Key adjustments:** - **Wider corridors:** Taxable investors should use wider rebalancing corridors than tax-exempt investors because each rebalancing trade has a tax cost. - **Tax-lot harvesting:** When you must sell, select the highest-cost-basis lots first to minimize realized gains. - **Tax-loss harvesting:** If an asset class has *losses*, rebalancing actually creates a tax benefit — harvest the loss and reallocate. - **Cash flow rebalancing:** Use new contributions, dividends, and required distributions to rebalance *without selling* — this avoids triggering gains entirely. **4. After-Tax Portfolio Optimization** The optimizer should use after-tax returns, after-tax volatilities, and after-tax correlations. Since taxes reduce the effective volatility of taxable assets (the government shares in both gains and losses), the after-tax efficient frontier shifts. **Exam Tip:** Vignettes often describe a high-net-worth individual with both account types. Be ready to recommend asset location, justify wider rebalancing corridors, and calculate after-tax returns. For more tax-aware portfolio strategies, explore our CFA Level III course materials.