model portfolio theory

Icky-Tasting Medicine

© Can Stock Photo / dolgachov

If you believe that living with ups and downs is an integral feature of long term investing, some aspects of customary investment practices seem rather curious.

The idea that volatility is risk is the root of the trouble, in our view. We believe volatility is simply the normal ups and downs, not a good measure of risk. A widely followed concept, Modern Portfolio Theory or MPT, adopts the approach that volatility is literally, mathematically, risk.

This approach attempts to work out “risk tolerance,” by which they mean willingness to endure volatility. If one is averse to volatility, then portfolios are designed with volatility reduction in mind.

Unfortunately, volatility reduction may result in performance reduction. But investments which do not fluctuate are not truly investments. Your bank account does not fluctuate, but it is not an investment.

We think beginning the conversation with an attempt to tease out willingness to endure volatility is a lot like a doctor working with a child to determine tolerance for icky-tasting medicine before making a prescription.

Our strategy is to impart what we believe about investing. We work with people to understand what part of their wealth might be invested for the long term, and whether they are comfortable with ups and downs on that fraction of it.

This necessarily involves learning about near and intermediate cash needs and income requirements, as well as talking about what it takes to live with the ups and downs. We invest a lot of time and energy into providing context and perspective so people might be better able to invest effectively. This process begins at the very beginning of our discussions with potential clients.

Clients, if you would like to talk about this or anything else, please email us or call.


All investing involves risk including loss of principal. No strategy assures success or protects against loss.

The opinions voiced in this material are for general information only and are not intended to provide specific advice or recommendations for any individual.

The Trouble with Zig and Zag Theory

© Can Stock Photo / chokniti

The idea behind massive diversification, owing a bit of everything, is that some things zig when others zag, keeping the whole bucket steadier. Great theory.

The problem is that things do not zig and zag ALL the time. When the big downturn comes, they all go down together. Oh, some things do not go down – but those things also tend to never go up, either.

The mathematical basis for massive diversification is Modern Portfolio Theory. It depends on different types of assets behaving more or less independently of one another – zigging and zagging. The lack of correlation is what drives the hypothetical usefulness of the theory.

In the big downturns, however, the correlations may converge. In plain language, in times of market stress, even independent investments may act as though they are related. The theory may not work due to systematic risks.

This is a real problem, because it is a theory that sometimes has the potential to drive investors to diversify into sectors and asset classes which may hold unknown risks, in the interest of avoiding market volatility.

This only makes sense if one defines volatility as risk, something to always be minimized and avoided. We think it makes more sense to understand volatility as an integral and necessary part of long term investing, a feature to be tolerated (or embraced) as the price of pursuing market returns over the long haul.

Investing in fluctuating markets with confidence requires us to know where our needed cash will come from – only long term money should be invested for the long term.

Clients, if you would like to talk about this or anything else, please email us or call.


The opinions voiced in this material are for general information only and are not intended to provide specific advice or recommendations for any individual.