100% shares strategy is nothing but recency bias. Prudent Asset Allocation requires a combination of all the three AA dimensions: Shares, Bonds and Money Markets. 2010 to 2022 made us forget Money Markets, but now as we learnt the lession and paid the price - its time to remember the magic traingle.
There is a simple logic why we need all the three. There are:
- Ex-Post Assets where the return was determined in the future
- Ex-Ante Assets where the return was upfront determined (for a certain period)
Prudent Asset Allocation calls for a combination of both, taking Ex-Post uncertainty (which is a source of additional risk premia) and Ex-Ante predictability (which gives us a pre-defined return). Everything else is a speculation on uncertainty. As economy and society tends to grow, such gamble tends to work out well - but it can at any time go terribly wrong. Or, if we omit Stocks and only invest on Bonds - it is an uber-reliance on predictability that harms return.
Both Ex-Post and Ex-Ante Assets are relevant for / evaluated after a certain period. Whereas Ex-Ante Assets can be further split into “low duration” and “high duration”, that concept doesn’t apply to most marketed Ex-Post Securities we want to invest in (unless we talk about High-Frequency Trading, Futures & Options).
In an idealistic world and notwithstanding High Frequency Trading Algos, our investment universe could be explained as a three point barbell consisting of:
| Short Duration | Long Duration |
---|
Ex-Ante | Short Term TIPS | Long-Term Treasuries |
Ex-Post | n/a | Shares |
Based on Efficient Market Hypothesis, we could argue that the combination of these three assets could explain all other assets, be it e.g. Cat Bonds (High Ex-Ante Short-Term Return plus some Ex-Post Risk/Premium), Senior Loans (Moderate Ex-Ante Mid-Term Return; limitted Ex-Post Risk/Premium)…
This is a post where I started from the Other End (Crazy Assets) and conclude that their result still equates to a combination of Stocks, Bonds and MM: Poll: Asset Allocation (other than stocks) - #21 by TeaGhost
or the respective PV Backtest:
Backtest Portfolio Asset Allocation (portfoliovisualizer.com)
The interesting thing is actually that, provided we leave out random events like Gold going crazy after the Gold ETF or de-PEG… out of the equation, the highest Sharp Ratios result from combining Shares, Bonds and MM together. You could either do this explicitly (Long Term Treasuries and Cash) or Implicitly (Mid Term Treasuries). A balanced portfolios sharpe ratio always beats a Stocks, Bonds, MM only Portfolio. Remember - when the dices fall in your favor - its easy to continue with a risky strategy but once dices go to the other spectrum… you will be super happy if you chose a strategy that optimizes your outcome (aka optimizes your sharpe ratio).
Long story short… don’t do 100% stocks only. Never. I know, it was the best strategy the past 50+ years but still - don’t do it. Never.