The traditional approach to building an investment portfolio with the aim of achieving a target wealth level for a set date in the future (typically retirement date) is relatively straight forward and involves discounting the future value of this portfolio to the present using an estimated discount rate which comprises a somewhat rough estimate of the expected annual growth rate of the portfolio. The major flaw with this approach is that the rate of return of the portfolio is very difficult to estimate, especially in the current volatile environment where visibility is relatively poor.
A far more intuitive and robust proposal would involve splitting an investment portfolio into two segments. One segment would be designated as the exposure that aims for capital preservation. This exposure contains investments that have very low risk and very low probability of experiencing drawdowns. The size of this segment should reflect the absolute strict minimum amount of wealth that the investor will need once he or she reaches retirement. The other segment comprises of the significantly riskier portion of the portfolio that the investors could afford to lose entirely but that should provide steady growth of the capital over the longer term.
You may wonder what the difference between this approach and a classic asset allocation portfolio comprised of a diversification between bonds and equities may be. The key difference is the the so called low risk allocation is there purely to preserve capital, it won't grow on its own but will increase in time through the reallocation of capital from the riskier segment, assuming that this segment does actually grow. The classical approach runs the risk of experiencing a sharp increase in correlations similar to 2008 when practically all asset classes were losing value simultaneously. Drawdowns in this novel approach should, instead, be limited to the "risk" portion of the portfolio.
The challenge in implementing this is twofold:
- How do you ensure that the "capital preservation" allocation does its job in a world where capital losses may be incurred even with money market deposits, through the uncertainty regarding counterparty risk (Lehman's being the recent example)
- The capital transfer from high risk to the low risk segments assumes that the high risk segment will grow through time. Nothing is less certain if we look at stock market performances over the more recent past!
Still, despite these challenges, the novel approach does provide a solution that is far more adapted to the current market environment and thus has a better chance of succeeding over the longer term.
