This book contains about 30 essays , meaning 30 ideas which can be read, ruminated and possibly applied in real life situations wherever they are applicable. Though the book is about finance, it draws considerable amount of research evidence from Biology, Math, Sociology,etc . At a 10,000 ft view , actually each discipline is nothing but an effort to understand the world using a set of constructs.
I would term Finance as a soft science rather than hard science where the discipline needs to be understood from various eyes . For a number cruncher , it becomes all the more important to realize that numbers,statistics is after all ONLY one part of the story in markets. One must consider market as a complex adaptive animal where numbers is ONLY one part of understanding. The more the mental models one has, the better one is equipped to understand what’s going on.
I will try to summarize the key idea from each of the 30 essays from the book.
- Process is more important than Outcome in Investing
Always consider success as a lucky realization unless you backtest it. Just because you make money using some trading rule does not mean that you are going to make it again. There is an undoubtedly a strong relation between good process used to make a decision and a good outcome. Think about it, this applies not only to investing but also to most of the things we do in life. Lets assume that you think that C# is the best language to create something that is needed, but somehow your skills are rusty and you would rather do it with VBA and build the same screens etc. Well, it might be probably good for short term, but can anyone use the tool apart from you? Is it Scalable ? Does it have a wow! element ? Is it extensible ?
- Constant see-saw between Investing considered as Business or Profession
This is the same point which Daniel Kahneman makes about the scale struggle. Money managers consider Investing as a business and work for the immediate goals and immediate returns (quarterly/yearly) but Business operates on a longer scale. I think instead of thinking of it as a Business or Profession, it is best if one can think of it as a Business and Profession. There will always be some assets which can be shorted at a professional scale and always some assets which can be longed at a business scale.
- Babe Ruth Effect
Well, this one is pretty well known. Focusing on frequencies and not on the Expected value can kill a risk manager. The same idea as Taleb’s Pi Lambda. In Mediocristan, Frequencies are important because payoff is pretty much symmetrical. But in Extremistan, it is important to understand the payoffs are not symmetrical. Infact they are very skewed and following frequentist approach is equivalent to being a sucker.
- Proper Categorization is the Key (Context based)
Most often than not, we categorize things and do not check the stationarity of the categories. My best ever read on categorization is an essay by Clay Shirky (Ontology is Overrated). Categorization as a subject has always fascinated me. In this book however the author says theories based on static categorization are not good. Well, we all know it, but how many of us actually keep that in mind when we go about theorizing, categorizing world events.
- Learn to translate uncertainty to Probability.
Degrees of Disbelief, Propensities and Frequencies are three ways to get to probability . Academic world is orgasmic about Frequentist world.Successful traders love propensities and uninformed trades live in the world of degrees of disbelief. For a trader who wants to trade by numbers, it is very important that he follows all the three ways depending on the context. For a plain vanilla options, frequentist is not a bad path to take. Well, you can rise over the usual theories known , do your own analysis on whether to follow mixture models, poisson+ gamma , whatever. However propensity based path needs to be taken too based on the context
- There is a Hot Hand in Investing, if not in baseball
Long streaks of success typically indicate luck imposed on great skill
Equity Premium Puzzle
Loss aversion and Myopia can explain the equity premium puzzle. Somehow I felt that is is the same time scale difference that is being brought out by the authorPart II : Psychology of Investing
- Link between Stress and Suboptimal portfolio Management
Essay beats the same point. Money managers operate on Shortening horizons, leading to stress to leading to suboptimal portfolio performance
Robert Caldini’s 30 year work is wonderfully summarized in this essay. The construct that there are 6 tendencies that spur a behavioral change : Reciprocation, Consistency , Social Validation, Looking, Authority and Scarcity . Each of these 6 tendencies are important when you need to think about the trading behavior change that can be observed in the market or trading rooms
- Emotion and Intuition in Decision making
- Guppy Love : Role of Imitation in Markets
Asymmetric information, Agency costs and Preference for conformity are three things which force traders to confirm. But this also leads to Herding.
- Beware of Behavioral Finance
This chapter was like a breath of fresh air in this book. Behavioral Finance follows the reasoning, Individuals are irrational and an aggregation of irrational individuals must lead to an irrational market. However the essay says that ” Markets can still be rational when investors are individually irrational”. Meaning there is a law of large numbers at play. The very fact that players operate at different time scales, investment styles and investment approaches means that diversity will always ensure collective rationality.. Which means whenever there are imbalances the market corrects itself. Well, Do I agree with this view ? I don’t think I am knowledgeable enough to form a view. But as such as a basic premise,I do believe in collective rationality and individual irrationality. But again, it is just a belief with no evidence to back it up
Essay on Keynes Expectation theory
Comparison of Markets to “Beauty Contest” and “El Farol Bar”. The idea that is conveyed in this essay is about deductive Vs inductive reasoning. Inductive is how we operate and it brings itself with a variety of bias. Deductive is how economics tries to operate , applying general principles to specific. In the case of markets, it ought to have been deductive but looking at market players, it appears inductive.This debate of deductive and inductive reasoning is brought out clearly.Part III: Innovation and Competitive StrategyI had a very strong tendency to skip over these essays for the simple reason that I have grown indifferent to the words strategy, competition, innovation etc. These are words, I remember , back in B school days, I was so fond of. It seemed as though using these words and thinking on these lines was leading to productive thinking. Over a period of time, I have realized that these are just fillers in conversations when you don’t have clear thinking. In fact all the buzz words that I learnt at B school, I have consciously tried to avoid over the past few years. These words look good in case studies and HBR articles … that’s all there is to it. If you have to do anything productive, I think it is better to ignore these words and think in simple terms.
With this kind of strong aversion towards such words, I was in no mood to go over these essays on strategy. But then I gave in, thinking that I might get at least some simple & meaningful thoughts from the next 7 essays. What did I find ?
As expected the entire part on strategy was like reading some old Bschool case..It bored me to death!! The only thing that I found was somewhat educative was about fitness landscapes. Again you can term it as old wine in new bottle. The other possible idea which deserves a mention is the analogy of chess players and traders
— Don’t look too far ahead
— Develop options and continuously revise them based on the changing conditions
— Know your competition
— Seek Small advantages
Again the above points are cliched, but the essay is a little better as it brings about nice chess analogies using these points.
Part IV: Complexity TheoryThis part of the book rocks!
Will summarize the last part of the book in my next post