Wednesday, May 13, 2009

Quantitative Momentum Investing vs. Fundamental Value Investing and (IN)efficient markets

After reading about Bill Miller´s Value Trust fund, two thoughts spring to mind:

Past results are no guarantee for future performance , therefore I would be careful about using any investment strategy for too long if the underlying economic reality and fundamentals have changed.


The market can stay irrational longer than you can stay solvent. John Maynard Keynes

Bill Miller was bullish on financials and homebuilders in 2006 and has progressively increased his positions and thereby his losses by consistently underestimating the depth, breadth and extent of the crisis. He declared in April 2008 that the crisis was over, and his bullishness, to me, is indicative of wishful thinking which is being used to rationalize expended energy, lost money and being wrong in calling the market bottom, his claims to the contrary notwithstanding.

That being said, Bill Miller´s value investing strategy has been burying quantitative momentum funds in the recent rally. From Zero Hedge:

Bill Miller is patting himself on the back for "burying" quant funds as this just released Bloomberg article notes: its timely appearance is critical as this is easily the most important theme in the current market dislocation, and thus Zero Hedge will post it in its entirety... Bill, after the worst year in his career, may be careful with the timing of his self-congratulations though...
IQS Commentary for March 2009


The IQS model was down -16.8% over the past 5 weeks, while the sector-neutral model was down 16.9%. [TD: discussion with the appropriate people indicate that April is on par for even worse performance, which is why Zero Hedge has been sounding the clarion call for normality - if market neutral Quants drop 40% in two months, it is truly game over]

Balance Sheet and Value added to performance, Improving Financials underperformed slightly, while Sentiment and especially Momentum underperformed.

What Happened?

What does it mean when momentum stops working? The stocks that lost the most over the past few months (dogs of the Dow and S&P 500?) outperform the most. (See IQS S&P pdf report for astonishing examples and IQS analysis.)

Without an economic catalyst, fundamentals based model would not predict (nor should they) this “dead cat” bounce. Are we witnessing a sustainable rally for these stocks? It’s possible, but not very likely. Some of these companies are financials, and the “risk” to this industry changes daily, but remains high. However, some of these companies are not financials, and investors are buying up these low priced stocks with the hope that the economic turnaround has started and will continue to improve. With reporting season upon us, guidance will help determine the direction and magnitude of the market during this period. If financials show an improvement, the market may take off. If most companies continue to post low or negative earnings without a clear picture of a turnaround, the market may retract.


The IQS dynamic weighting system made small changes this month to the weights. With the market and economic conditions still weak.

Some weight was added to Improving Financials (mid), while a little weight reduced Momentum (mid), from Value (low), Balance Sheet (mid).

What is the IQS Model telling us about Sectors? No significant changes from last month.

Best – Aerospace, Retail, Medical, Utilities, Consumer Staples

Middle –Business Services, Oils/Energy, Industrial Parts, Transportation, Technology, Basic Materials

Worst – Autos, Finance, Construction, Conglomerates, Consumer Discretionary
We are at a critical crossroads for the future of efficient markets. If the bear market rally persists, Bill Miller and 401(k) holders will be happier temporarily, however the end result would be a broken market. Readers who took offense to the photo of the Challenger explosion earlier, should wake up and realize that we are on the verge of the very same event occurring within the fabric of the free and efficient market system. The threat to the equity markets is not being exaggerated. If the powers that be are intent on rising stock prices one day at a time continually, then even as retail investors enjoy another day of moderate gains, in a few short days/weeks markets will reach a point of no return, and the resultant collapse in confidence in the free market system will force the majority of investors to forever depart from investing in equity markets. The consequences of this would be beyond the scope of even this blog.

To many this may seem alarmist and overly pessimistic given the “green shoots” everyone is talking about; only time will tell. My reason for posting this, though, is to illustrate that relying on only the value investing strategy would have led to huge losses in the past two years and to gains since March 9, and that relying on quantitative momentum strategies in the same time frame would have led to gains by being short exactly Bill Miller´s favorite sectors, as John Paulson was and managed to earn $3.6 billion for himself in 2008, and to losses in the current rally. Diversification, in my mind, means not only different asset classes, but also using strategies that adapt to changing circumstances.

Bill Miller does not share this view:

From Bill Miller´s April Commentary:

Our portfolios, it should be stressed again, are not built based on macroeconomic forecasts, or expectations about the direction of equity markets in the next few months. They are constructed based on long-term considerations of value under average expected conditions over the next several years. That means that we believe the economy and the stock market will grow over the next few years, even if they do or don’t this year, and that businesses will earn returns on capital consistent with their competitive advantages, the underlying economics of their industries, and the capability of their managements.

To me, it seems that Miller assumes an underlying objective economic reality that is independent of the actions and expectations of the actors. I would point to Keynes´s Paradox of Thrift and Fisher´s Debt Deflation Spiral as reasons why market conditions may not conform to “average expected conditions.”

To say nothing of the lurking bad loans on banks´ balance sheets and their fictitious valuation of “troubled assets” which are once again based on their hubris laden overreliance on risk management models which may not apply given that the fundamental assumptions they are based on have changed or will do so dramatically in the near future. I would further urge Miller and, indeed, all investors, to take a good look at George Soros´s Theory of Reflexivity:

I must state at the outset that I am in fundamental disagreement with the prevailing wisdom. The generally accepted theory is that financial markets tend towards equilibrium, and on the whole, discount the future correctly. I operate using a different theory, according to which financial markets cannot possibly discount the future correctly because they do not merely discount the future; they help to shape it. In certain circumstances, financial markets can affect the so-called fundamentals which they are supposed to reflect. When that happens, markets enter into a state of dynamic disequilibrium and behave quite differently from what would be considered normal by the theory of efficient markets. Such boom/bust sequences do not arise very often, but when they do, they can be very disruptive, exactly because they affect the fundamentals of the economy.” I did not have time to expound my theory before Congress, so I am taking advantage of my captive audience to do so now. My apologies for inflicting a very theoretical discussion on you.

The theory holds, in the most general terms, that the way philosophy and natural science have taught us to look at the world is basically inappropriate when we are considering events which have thinking participants. Both philosophy and natural science have gone to great lengths to separate events from the observations which relate to them. Events are facts and observations are true or false, depending on whether or not they correspond to the facts.

This way of looking at things can be very productive. The achievements of natural science are truly awesome, and the separation between fact and statement provides a very reliable criterion of truth. So I am in no way critical of this approach. The separation between fact and statement was probably a greater advance in the field of thinking than the invention of the wheel in the field of transportation.

But exactly because the approach has been so successful, it has been carried too far. Applied to events which have thinking participants, it provides a distorted picture of reality. The key feature of these events is that the participants’ thinking affects the situation to which it refers. Facts and thoughts cannot be separated in the same way as they are in natural science or, more exactly, by separating them we introduce a distortion which is not present in natural science, because in natural science thoughts and statements are outside the subject matter, whereas in the social sciences they constitute part of the subject matter. If the study of events is confined to the study of facts, an important element, namely, the participants’ thinking, is left out of account. Strange as it may seem, that is exactly what has happened, particularly in economics, which is the most scientific of the social sciences.

Classical economics was modeled on Newtonian physics. It sought to establish the equilibrium position and it used differential equations to do so. To make this intellectual feat possible, economic theory assumed perfect knowledge on the part of the participants. Perfect knowledge meant that the participants’ thinking corresponded to the facts and therefore it could be ignored. Unfortunately, reality never quite conformed to the theory. Up to a point, the discrepancies could be dismissed by saying that the equilibrium situation represented the final outcome and the divergence from equilibrium represented temporary noise. But, eventually, the assumption of perfect knowledge became untenable and it was replaced by a methodological device which was invented by my professor at the London School of Economics, Lionel Robbins, who asserted that the task of economics is to study the relationship between supply and demand; therefore it must take supply and demand as given. This methodological device has managed to protect equilibrium theory from the onslaught of reality down to the present day.

I don't know too much about the prevailing theory about financial markets but, from what little I know, it continues to maintain the approach established by classical economics. This means that financial markets are envisaged as playing an essentially passive role; they discount the future and they do so with remarkable accuracy. There is some kind of magic involved and that is, of course, the magic of the marketplace where all the participants, taken together, are endowed with an intelligence far superior to that which could be attained by any particular individual. I think this interpretation of the way financial markets operate is severely distorted. That is why I have not bothered to familiarize myself with efficient market theory and modern portfolio theory, and that is why I take such a jaundiced view of derivative instruments which are based on what I consider a fundamentally flawed principle. Another reason is that I am rather poor in mathematics.

It may seem strange that a patently false theory should gain such widespread acceptance, except for one consideration; that is, that all our theories about social events are distorted in some way or another. And that is the starting point of my theory, the theory of reflexivity, which holds that our thinking is inherently biased. Thinking participants cannot act on the basis of knowledge. Knowledge presupposes facts which occur independently of the statements which refer to them; but being a participant implies that one’s decisions influence the outcome. Therefore, the situation participants have to deal with does not consist of facts independently given but facts which will be shaped by the decision of the participants. There is an active relationship between thinking and reality, as well as the passive one which is the only one recognized by natural science and, by way of a false analogy, also by economic theory.

Here is a great quote from Keynes that I find as relevant now as it was when he wrote it.

Actually, however, we have, as a rule, only the vaguest idea of any but the most direct consequences of our acts. Sometimes we are not much concerned with their remoter consequences, even tho time and chance may make much of them. But sometimes we are intensely concerned with them, more so, occasionally, than with the immediate consequences.

Now of all human activities which are affected by this remoter preoccupation, it happens that one of the most important is economic in character, namely. Wealth. The whole object of the accumulation of Wealth is to produce results, or potential results, at a comparatively distant, and sometimes at an indefinitely distant, date. Thus the fact that our knowledge of the future is fluctuating, vague and uncertain, renders Wealth a peculiarly unsuitable subject for the methods of the classical economic theory. This theory might work very well in a world in which economic goods were necessarily consumed within a short interval of their being produced. But it requires, I suggest, considerable amendment if it is to be applied to a world in which the accumulation of wealth for an indefinitely postponed future is an important factor; and the greater the proportionate part played by such wealth-accumulation the more essential does such amendment become. By "uncertain" knowledge, let me explain, I do not mean merely to distinguish what is known for certain from what is only probable. The game of roulette is not subject, in this sense, to uncertainty; nor is the prospect of a Victory bond being drawn. Or, again, the expectation of life is only slightly uncertain. Even the weather is only moderately uncertain. The sense in which I am using the term is that in which the prospect of a European war is uncertain, or the price of copper and the rate of interest twenty years hence, or the obsolescence of a new invention, or the position of private wealth owners in the social system in 1970. About these matters there is no scientific basis on which to form any calculable probability whatever. We simply do not know. Nevertheless, the necessity for action and for decision compels us as practical men to do our best to overlook this awkward fact and to behave exactly as we should if we had behind us a good Benthamite calculation of a series of prospective advantages and disadvantages, each multiplied by its appropriate probability, waiting to he summed.

How do we manage in such circumstances to behave in a manner which saves our faces as rational, economic men? We have devised for the purpose a variety of techniques, of which much the most important are the three following:

(1)We assume that the present is a much more serviceable guide to the future than a candid examination of past experience would show it to have been hitherto. In other words we largely ignore the prospect of future changes about the actual character of which we know nothing.
(2) We assume that the existing state of opinion as expressed in prices and the character of existing output is based on a correct summing up of future prospects, so that we can accept it as such unless and until something new and relevant comes into the picture.
(3) Knowing that our own individual judgment is worthless, we endeavor to fall back on the judgment of the rest of the world which is perhaps better informed. That is, we endeavor to conform with the behavior of the majority or the average.

The psychology of a society of individuals each of whom is endeavoring to copy the others leads to what we may strictly term a conventional judgment. Now a practical theory of the future based on these three principles has certain marked characteristics. In particular, being based on so flimsy a foundation, it is subject to sudden and violent changes. The practice of calmness and immobility, of certainty and security, suddenly breaks down. New fears and hopes will, without warning, take charge of human conduct. The forces of disillusion may suddenly impose a new conventional basis of valuation. All these pretty, polite techniques, made for a well-panelled Board Room and a nicely regulated market, are liable to collapse. At all times the vague panic fears and equally vague and unreasoned hopes are not really lulled, and lie but a little way below the surface.

Perhaps the reader feels that this general, philosophical disquisition on the behavior of mankind is somewhat remote from the economic theory under discussion. But I think not. Tho this is how we behave in the market place, the theory we devise in the study of how we behave in the market place should not itself submit to market-place idols. I accuse the classical economic theory of being itself one of these pretty, polite techniques which tries to deal with the present by abstracting from the fact that we know very little about the future. I daresay that a classical economist would readily admit this. But, even so, I think he has overlooked the precise nature of the difference which his abstraction makes between theory and practice, and the character of the fallacies into which he is likely to be led.

Keynes, John Maynard (1937). `The General Theory of Employment`, Quarterly Journal of Economics, 51. cited in Shaw, G.K. (1988). The Keynesian Heritage: Volume I. pp.11-13

So, I am inherently skeptical of any theory which holds that it is in possession of the truth, especially those which have thinking humans as participants and are based on unrealistic axiomatic assumptions. Furthermore, I am in favor of what Arthur Koestler called open systems which can be changed and adapted as needed, as opposed to closed systems which profess to explain everything. Not even physics manages to explain everything at the macro or cosmological level and the micro or quantum level in a unified theory; therefore, I am even more doubtful that investment or economic theories can accomplish the feat of being always valid at every level.

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