(Updated March 31, 2023).
"Do Not Confuse High Returns With Sustainability"
The most important measure of portfolio performance for those in or approaching retirement is return relative to drawdowns. The higher this ratio, the higher the withdrawal rate the portfolio can sustain.
The financial services industry uses a Monte Carlo simulation of possible historical outcomes to construct a "Safe Withdrawal Rate". I use what I believe to be a far more conservative approach which uses historical Compound Annual Growth Rates and historical Maximum Drawdowns.
I begin with every investor's worst fear ... a Bear Market which begins immediately upon making the investment rather than one which “possibly” occurs sometime in the future.
Sustainable Withdrawal Rate Calculation
The calculation is both simple and conservative.
- Account Balance – Maximum Drawdown = Remaining Balance
- Remaining Balance x Compound Annual Growth Rate = Average Return
- Average Return x 50%* = Sustainable Annual Return
- Sustainable Annual Return / Account Balance = Sustainable Withdrawal Rate
*Leave 50% as a safety net for inflation, portfolio growth, and contingencies
The Conservative Logic of our Sustainable Withdrawal Rate
- We assume the worst case of an immediate Bear Market decline
- The Bull Market which follows the Bear Market is likely to produce returns above the CAGR for the full Bear+Bull cycle
In short, we are building a Sustainable Withdrawal Rate which assumes the worst case for drawdowns and less than best case for returns.
Example Calculation Vanguard Balanced Index Fund (VBINX)
Time Period: three Market Cycles January 2000 through March 2023
Compound Annual Growth Rate: 5.8%
Maximum Monthly Drawdown Calculated: 32.6% (February 2009)
- $100,000 – $32,600 = $67,400 (assume an immediate Bear Market reduces portfolio by the Maximum Monthly Drawdown of 32.6%)
- $67,400 x .058 = $3909 (apply the Compound Annual Growth Rate to reduced portfolio)
- $3909 x 50% = $1,955 (assume we can withdraw half of the CAGR)
- $1,955 / $100,000 = 1.9% (we include this number in every Performance Table)
Had the Maximum Drawdown been limited to 7%+-, the Sustainable Withdrawal Rate would be 42% higher!
- $100,000 – $7,000 = $93,000
- $93,000 x .058 = $5,394
- $5394 x 50% = $2697
- $2,697 / $100,000 = 2.7%
- The Sustainable Withdrawal Rate is based on very conservative assumptions
- Do Not Confuse High Returns With Sustainability
- A high Sustainable Withdrawal Rate requires both high returns and low drawdowns
The TAAStrategies excel in providing both high returns and low drawdowns