Zero Hedge is one of my favorite blog on the risk analysis and for the global events, the blog argues that we are living in the Golden Age of Central Bankers, and that wreaks havoc on the fundamental nature of market expectations data.
- The VIX (Volatility Index) is not a reliable measure of market complacency.
- The wisdom of crowds is non-existent.
- Fundamental risk/reward calculations for directional exposure to any security are problematic on anything other than a VERY long time horizon.
- I’d rather be reactive and right in my portfolio than proactive and wrong.
The Golden Age of the Central Banker is a time for survivors, not heroes. And that’s the real moral of this story.
Let’s dig deep to understand the most basic question in risk management. Do you understand the fundamental nature of your data? Our business incentivizes us to build complex and ingenious models and data analysis systems in order to generate an edge or dodge a bullet. But are we building our elaborate mental constructs on solid ground?
Volatility is a measurement of how violently the returns of a security jump around, and in professional investment circles the word “volatility” is typically used as shorthand for risk – the higher the volatility, the greater the embedded risk. There are some valid concerns and exceptions to this conflation of the two concepts, but by and large I think it’s a very useful connection.
Within the general concept of volatility there are two basic ways of measuring it. You can look backwards at historical prices over some time period to figure out how violently those prices actually jumped around – what’s called “realized volatility” – or you can look forward at option prices for that same security and figure out how violently investors expect that prices will jump around in the future – what’s called “implied volatility”. Both flavors of volatility have important uses, even though they mean something quite different. For example, a beta measurement (how much a security’s price moves relative to an underlying index) is based on realized volatility. On the other hand, the VIX index – the most commonly reported gauge of overall market risk or complacency – is entirely based on the implied volatility of short to medium-term options on the S&P 500.
The big drawback to using realized or historical volatility is that it is, by nature, backwards looking. It tells you exactly where you’ve been, but only by extrapolation provides a signal for where you are going. In a business where you always want to be looking forward, this is a problem. Using realized volatility means that you will always be reacting to changes in the broad market characteristics of your portfolio; you will never be proactive to looming changes that might well be embedded within the “wisdom of the crowd” as found in forward-looking options prices. If you’re relying on realized volatility, no matter how sensitively or smartly you set the timing parameters, you will always be late.
Yes, there is useful information in implied volatility for many purposes. But no, not for the purpose of asset allocation. Why not? Because we are living in the Golden Age of Central Bankers, and that wreaks havoc on the fundamental nature of market expectations data.
Source : Zero Hedge