more on risk as volatility

volatility as risk

I was listening to Bloomberg radio the other day when a talking head who usually has interesting things to say (an increasing rarity on Bloomberg) began to “explain” how 2015 was a very risky year for stocks.  This, even though the S&P 500 was ending December in basically in the same place it started out in January.

Measures of interday change in individual stock prices were also relatively benign   …but, he said, intraday price movements in stocks were unusually high.  Therefore, stocks were riskier than usual.

Yes, in a very tortured sense…or for a day trader who’s consumed by hour-to-hour price movements…that might be so.  For you and me, though, that’s crazy.


Last September 14th I wrote another post about the academic notion that investment risk can be defined as day-to-day volatility, i.e., the daily change in the price of a given security.

The main pluses for this idea are that it’s simple, the data are readily available and you don’t have to know anything about the security in question or the goals of the holder.

In my earlier post, I pointed out that this notion led to catastrophic results in the late 1980s-early 1990s for institutional holders of commercial real estate and junk bonds.  Neither traded very often, so the daily price–as determined by the last actual transaction–rarely changed. Volatility was negligible.  What a surprise when lots of people wanted to sell at the some time, only to find that low volatility didn’t represent safety.  It signaled illiquidity–there were no buyers at anywhere near the last trade.

not a 100% useless concept

There is a sense in which volatility may be important, though.  Over several year periods, stocks tend to follow an up and down pattern that mirrors the business cycle, with stocks leading the economy by about six months.  Over longer periods, stocks tend to advance on trend around the rate of growth in reported profits, which has historically been about +8% per year in the US.


If you’re in your thirties or forties and saving for your retirement or to pay for your young children’s college tuition, then daily or even business cycle fluctuations in stock prices are irrelevant now.  Investing in stocks that have low volatility–which usually also comes with low appreciation potential–makes no sense at all, despite the notion’s academic pedigree.

On the other hand, if you’re saving, say, for a wedding or to buy a house and will need the funds in six months or a year, then having it in stocks is probably a bad idea.  That’s because prices could easily be 10% below today’s level when you need the money.  Just look at a chart of the S&P 500 in 2015–which chronicles a mid-summer S&P swoon– to see what I mean.  In this case, keeping your money in (low-volatility) cash is the better course of action.





risk and volatility


I think that defining what risk is is the most difficult topic in finance/investing.

I’m not sure there’s one answer that fits everyone and everything.

We do know that individuals’ perception of what risk entails changes as they age or as their wealth increases; they become more conservative.  We also know that appearances can be deceiving.  A model with a perfectly proportioned body may be clumsy or a terrible athlete.  Experience counts for something, as well.  Situations that appear risky when a neophyte is in control, like in doing brain surgery, may in fact be relatively safe in the hands of an expert.  Information is important, too, like having enough data or experience to know who is the beginner and who is the well-trained seasoned pro.

risk as volatility

Academic finance, and following its lead, pension consultants and their pension fund clients, have all chosen to reduce this complexity to a single concept, risk = volatility.  In other words, the magnitude of day to day price changes in securities. This can be expressed either in absolute form or relative to some benchmark, and may be measured over differing time periods.

Defining risk as volatility has three big advantages:

–easy data availability

–quantitative form


In a world where no one runs with scissors or texts while driving, or where there’s never a flood, a tornado or huge food items falling from the sky (like in Chewandswallow), that would be enough.

In practice, however, volatility isn’t such a hot measure.

On a very abstract level, there’s no recognition of the issue that philosophers have been pondering for the past two centuries or so–that groups may not be connected by every member having a single thing in common.  One alternative is the possibility of “family resemblances” popularized by Ludwig Wittgenstein over a half-century ago.  So maybe there isn’t one common factor that constitutes risk.

On a more practical level, in the real world not everyone has the same information.  History also shows that markets periodically become highly emotional, either wildly optimistic or deeply pessimistic.  My conclusion, based on decades of experience, is that the results of daily trading don’t constitute infallible indicators.  Quite the opposite–most often one should take the evidence of daily trading with a grain of salt.

…but does it trade?

To my mind, though, the most striking failure of volatility as a risk measure is that it doesn’t take liquidity into account.

An example of what I mean:

In the mid 1980s, I came across for the first time academic articles that touted real estate as the most attractive of major asset classes.

How so?

The argument was that since the end of WWII real estate had not only a higher annual rate of return than stocks or bonds, but it also had the lowest average price volatility of the three.  Not only did real estate deliver the highest absolute gains, but adjusting for its low “risk” property ownership looked even better.  This was an odd result, because one typically thinks that reward and risk are directly correlated, not inversely.  But no one questioned it.

real estate

Anyone who has owned a home over an extended period of time, to say nothing of owners of commercial or office real estate, knows this is loony.  In bad times, bank finance disappears and, along with this, so too transactions.  During 1981-83 in the US, when I experienced this phenomenon first-hand, houses could only be sold at extremely steep discounts to pre-recession prices–or to owners’ notions of fair value based on rental equivalents.  Potential buyers made very low-ball offers, prospective sellers took their homes off the market, and no transactions happened.  In the very narrow sense, therefore, volatility was low.  But that was because there were no sales to demonstrate how the market had deteriorated, prices were stable.  You just couldn’t sell.

junk bonds

The collapse of the junk bond market in the late 1980s demonstrated the same idea.  Junk bonds had been touted as having “all the rewards of stocks with all of the safety of bonds.”  The safety part proved an illusion.  The apparent stability of the net asset values of junk bond funds ended up resting in large part on the fact that the bonds they held seldom traded.  So every day the funds priced themselves using more or less the last trade, which might have been weeks ago–and which might not reflect current circumstances.  This idyll lasted until funds began to have net redemptions, forcing them to sell bonds at real market prices, which were often way below their carrying value on  fund books.


Olivier Blanchard on economics

Olivier Blanchard, the chief economist of the IMF during the financial crisis, is now leaving that organization for the Peterson Institute.  Monday’s Wall Street Journal contains excerpts from his reflections on the state of the world–and of macroeconomics as a discipline–that are contained in full in the most recent IMF Survey (the WSJ has all the high spots, I think).

What caught my eye was Mr. Blanchard’s admission that macroeconomics was caught flat-footed by the recent global financial crisis.

How so?

My paraphrase of his explanation, with which he might not want to agree, is that:

–the discipline believed that a small, highly abstract set of theoretical relationships among the main moving parts of national economies and their external links, a set fleshed out in the wake of the 1930s depression, was enough to ensure they had complete understanding of the 21st century world.  That has turned out to be completely wrong.  In particular, the idea that economic policy makers need not bother to learn the details of the functioning of the banking system or about the inner workings of the small number of global mega-banks proved to be a costly error.

Yes, it took a humongous crisis to shake macroeconomists’ core beliefs and to begin to lessen their contempt for microeconomics.

What strikes me the most is that there is, as far as I can detect, no similar crisis of conscience on the part of academic finance.  The theoretical underpinnings of this discipline lie in quasi-religious beliefs of the 18th century and are far more suspect.  Its theoretical framework has no failed to predict or explain any of the financial crises that have occurred since its creation in the 1960s-70s.  In fact, the speculative frenzy and subsequent financial meltdown of the early 1970s, one of the greatest counterexamples to academic financial theory postulates, was occurring outside the windows of the ivory tower as academics were nailing down its main planks.


It takes a lot of intellectual fortitude for a researcher spending a lifetime dealing with abstractions to admit that knowledge of the “plumbing” behind the walls of his theoretical house actually matters.  A renaissance of macro thinking appears to be in the offing, as a result, of this realization in economics.  One can only hope that the same light one day shines on academic finance.  I’m not willing to bet, however, that this will happen any time soon.


stock options and stock buybacks

I first became aware of the crucial relationship between stock option grants and stock buybacks in the late 1990s.

I was on a research trip to San Francisco, where I had dinner with the new CEO, a turnaround specialist, of a chip design and manufacturing company with a checkered history.

In the course of our conversation, he said that one of his objectives was to ensure he retained top talent.  He went on to mention, as if it were a matter of course, that he would do so by having his firm issue enough stock options to transfer ownership of 6% of the company each year to workers (I’m pretty sure 6% was the number, but it could have been 8%).

I was shocked.

My first thought was that after eight years (six years, if the 8% is correct), there’d potentially be 50% more shares out.  This would massively dilute the ownership interest of any shares I might buy for clients.

My second was that I would have to evaluate the potential for massive positive earnings surprises that would make the stock skyrocket if the turnaround were successful, against the steady erosion of my ownership interest through stock option issuance.  (I decided to bet on skyrocket, which ended up being the right thing to do).

My third was that eventually suppliers of equity capital like me would have to question whether the kind of ownership shift this CEO was presenting as normal tilted rewards too far in the direction of management.


After this experience, I began to look much more carefully at the share option schemes of companies that might potentially be in one of my portfolios.  I noticed that in many cases companies had stock buyback programs–pitched as a “return to shareholders” of profits, sort of like dividends–that almost exactly offset the dilution from the issuance of new stock to employees.

This isn’t the case for all companies, but my observation is that it is for many.  I don’t think this is a coincidence.

Part of the rational for buybacks, it seems to me, is simply to prevent dilution of earnings per share, which would arguably help no one.  But at the same time, for the casual observer who looks only at share count and at earnings vs. eps, it obscures how big the corporate stock option issuance plan is.  I don’t think this is an accident, either.  Yes, the information is all in the SEC filings, but the reality is that even many investment professionals don’t read them.

That’s what I find problematic about stock buybacks–that I feel they’re misleadingly described as a shareholder benefit, while their purpose is to play down the level of key employee compensation.