The Risk-Reward Blind Spot Part 1: Pre-Tax vs. Post Tax Returns
- Brandon Mull, CFA, CFP®
- Jun 5
- 4 min read
The Risk-Reward Blind Spot Part 1: Pre-Tax vs. Post Tax Returns We frequently encounter investors who are highly satisfied with a 10% annual average return generated from their portfolio in its entirety, or a specific corner of it, depending on their risk level. On paper, a double-digit return sounds like an absolute home run. But looking strictly at top-line numbers isn’t the only way to track your financial pace. If you are a high earner living in a high-tax state, your marginal tax rate can easily hover around 40% or more when you factor in Net Investment Income Tax (NIIT), additional Medicare tax, and possibly Alternative Minimum Tax (AMT). When evaluated through an after-tax lens, that pristine 10% return shrivels down to a realized return closer to 6% or 7%.[1] |
While a 6% to 7% net return is still solid, it fundamentally alters the risk/reward profile of the investment. Generally speaking, higher expected returns require taking on greater levels of structural risk. If you take on the volatility or liquidity hazards of a 10% asset, but hand a massive slice of your gains over to the government without shrinking your risk exposure, your actual return per unit of risk declines. It could even be argued that you are being undercompensated for the hazards you are carrying. [2] Tax Drag: Long-Term Math The inescapable fact of investing is that Uncle Sam always feels entitled to a slice of your good fortune. Over an extended timeline, ignoring the fact you’re running against this financial headwind can act as a compounding drag on wealth accumulation.[3] To see this friction in action, let's look at the real-world mathematical trajectory of a $1,000,000 initial investment compounded over a 20-year horizon. The table below illustrates how a $1 million portfolio grows over 20 years, comparing a 10% pre-tax track against the reality of a 6% to 7% after-tax drag.  Source: Marathon Wealth Advisors Over a 20-year period, tax drag erodes between $2.85 million and $3.52 million of the total compounding potential. Up to 52.3% of your long-term outcome can be completely lost to tax friction. Two portfolios can follow the exact same investment track and achieve identical pre-tax returns, yet produce wildly divergent results in terms of dollars in your nest egg. Managing After-Tax Funds: Tactically Fighting Back While you cannot eliminate the government's appetite for tax, you can control how efficiently you manage your accounts. To maximize your after-tax return per unit of risk without taking on unnecessary investment hazards, your taxable brokerage funds require active, tax-focused oversight. We focus heavily on a few core operational pillars to shield after-tax wealth:
Ultimately, defensive financial planning isn't about blindly chasing the highest top-line, pre-tax numbers. It is about maximizing what you actually keep. Look at your wealth through an after-tax filter, deploy active tax management, and focus on the metrics that actually build enduring security across full market cycles. In the weeks ahead we’ll touch on other important aspects of tax based portfolio planning: retirement plans, pre-tax IRA deferrals, Roth savings, and backdoor Roth conversions. Recent readings: 2025 – 2026 Planning Priorities – Katten Muchin Rosenman LLP U.S.-Iran deal hopes drive sentiment across markets – T. Rowe Price As Wealth Firms Grow, Some Clients Look for Smaller Alternatives – Institutional Investor |