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  • Transcription of interview with James Owen Weatherall on June 3, 2013.

  • Douglas Goldstein, CFP�, Financial Planner & Investment Advisor

  • James Owen Weatherall is an Assistant Professor of Logic and Philosophy of Science at the

  • University of California in Irvine. He recently came out with a new book called the Physics

  • of Wall Street.

  • Douglas Goldstein, financial planner & investment advisor, interviewed Weatherall on Arutz Sheva

  • Radio.

  • Douglas Goldstein: How you got started on writing this book?

  • James Owen Weatherall: I was a graduate student in physics and now I teach philosophy and

  • the foundations of physics but I got my start in physics. I was a graduate student in physics

  • just as the world financial crisis hit in 2007 and 2008. I was pretty fascinated by

  • the media coverage of the crisis. It seemed to put a lot of focus on people who quite

  • surprising to me who had no background in finance, people whose backgrounds were like

  • mine, people who had background in fields like math and physics want to understand how

  • it was these so-called quants had gotten into Wall Street and what kind of effects theyve

  • had.

  • Douglas Goldstein: Do you find any parallel to anything that they were doing that made

  • sense in both the physics and the finance world?

  • James Owen Weatherall: I found quite a bit. One of the questions that I was most interested

  • in answering was just how it was that physicists and mathematicians had gotten into Wall Street

  • in the first place. It seemed like through the fact that they had and I wanted to know

  • how they had gotten there, what they were doing, and what sorts of ideas they had brought

  • along.

  • Douglas Goldstein: In your research, what were some of the similarities that you began

  • to discover?

  • James Owen Weatherall: Some of the most influential ideas in particularly mathematical finance

  • over the last 50 or 100 years actually originated with people who had backgrounds in physics

  • and in some cases in mathematics. It wasn�t simply that there were parallels between the

  • theories that one such you opened a finance book and the theories that you saw if you

  • open the physics book. In fact there has actually been a movement of ideas that physicist had

  • gotten interested in finance and had brought ideas with them.

  • Douglas Goldstein: Is this just because paychecks are higher on Wall Street?

  • James Owen Weatherall: Strikingly no. First of all, some of the first people who did this,

  • some of the people who really laid the foundation never went to work on Wall Street and never

  • seemed to have made much money. In fact, the first two physicists who I talked about in

  • the Physics of Wall Street were both people who in some sense concluded that there was

  • no way to make a profit using these sorts of ideas. They had thought that they had proved

  • mathematically that the market was a random and that things like stock picking, anything

  • but index fund investment was just going to be useful to you. They never made a profit

  • or went to work for bank stocking later.

  • Douglas Goldstein: Can you give us an example and maybe keep it on the level of a personal

  • finance show of something in physics that youve seen paralleled in investing?

  • James Owen Weatherall: One idea is the options pricing model. This is actually a great example

  • because the options pricing models themselves aren�t really ideas from physics but they

  • are based on ideas about randomness and an idea particularly called a �random walk

  • so how do you think about a particle moving randomly for instance a fluid. You can use

  • the same sort of math described how a stock price moved randomly over time and come out

  • with a theory for how the probability is will change over time and once youve had that

  • theory, it turned out that there were physicists who did this as well, apply that theory and

  • figure out how the price of an option should vary with the price of underlying stock.

  • Douglas Goldstein: This does not necessarily make a trading algorithm that you could say

  • as right more than 50% at a time?

  • James Owen Weatherall: That by itself doesn�t. In fact, that�s why some of these earliest

  • physicists came to believe that they had not come up with ideas that could make profits

  • but of course that change, there wouldn�t be physicist on Wall Street if everyone still

  • believe that. One of the people who I talk about in the book who really made a connection

  • was a guy named Ed Thorp. Ed Thorp was trained as a physicist and a mathematician at UCLA.

  • He has a PhD in mathematics. He was very interested in gambling. He had worked with the first

  • person to prove mathematically that you could have an advantage in black jack if you counted

  • cards. Along the way, he discovered something called the Kelly Betting Criterion which is

  • a mathematical formula that comes out of electrical engineering information theory about how information

  • should affect trading strategies or betting strategies. That idea which was essentially

  • an idea from electrical engineering to turn the sorts of options pricing models that people

  • were thinking about into strategies that could make money more than half a time. These are

  • the first, by any reasons, standard first quantity hedge fund.

  • Douglas Goldstein: Is that parallel to people having problems looking at certain elements

  • because by simply looking at them, the protons hitting them change the nature of them?

  • James Owen Weatherall: There is an analogy to that in finance. One of the big challenges

  • that face people who try to use mathematics to understand market is that the kinds of

  • models that we end up using can change how markets behave. If everyone starts using the

  • same sort of model, that will change how prices vary and we in fact saw it in the 1980s. A

  • particular options pricing model know as a Black-Scholes model became very popular and

  • it used to be that prices did not agree that well with that model and then during the 1980s,

  • they gradually shifted so that they agreed perfectly with the model and that best explanation

  • for this was that everyone was using the model. This means that there�s now a challenge.

  • This is one of the theses of the book, models aren�t perfect. There are assumptions that

  • go into them and models can fail. The trick is to understand how these assumptions to

  • work and when they might fail, but if everyone is using the same model, it can mask the ways

  • in which the assumptions are beginning to fail causing problems so the challenge to

  • market modelers to figure out how to stand half of markets that are changing in response

  • to what they do.

  • Douglas Goldstein: One of the things you described in your book is how a geophysicist uses a

  • model designed for earthquakes to predict a massive stock market crash. How does that

  • work? Is there something we can learn from that as well?

  • James Owen Weatherall: His name is Didier Sorneth who is a professor at ETH Zurich in

  • Switzerland. He got a start actually working on when pressure tanks on European space craft

  • would explode. He developed a way of predicting this apparently random explosions and then

  • he took the mathematics he developed there and applies them to earthquakes and try to

  • identify situations where catastrophic earthquake would occur and then realized that a similar

  • sort of idea maybe could be use to predict stock market crashes. In fact, he has successfully

  • predicted a number of crashes over the last roughly 15 years starting in 1997.

  • The thing that he is doing isn�t so different from what a lot of sort of ordinary investors

  • would think as probably right. His idea is that markets crash in part because of external

  • influences, the economy going south but also in part because it�s something to do with

  • market conditions, how investors were actually behaving. That�s something to do with for

  • instance an idea of groupthink or crowd behavior, the ideas that before crashes often you can

  • have a kind of market hysteria. So if you think something about the dot.com crash, there�s

  • an idea that lots of people got pulled into this new industry and with the idea that it

  • was going to be extraordinarily successful, put a lot of money in it, stocks rose very

  • quickly and then couldn�t sustain those gains. His idea is simply to look for situations

  • where the market might have that kind of math hysteria going on, the ideas there are statistical

  • patterns you might expect to be associated with situations where everyone is trading

  • for instance on the same sorts of information.

  • Douglas Goldstein: Isn�t just kind of a crowd mentality which is what we then refer

  • to as a bubble?

  • James Owen Weatherall: The idea is that actually bubbles should have certain statistical patterns

  • associated with them. If you want to predict the crash, don�t predict the bit of news

  • that�s going to make everyone sell. Identify the situations where there is a bubble where

  • a bit of outside news could make a big difference.

  • Douglas Goldstein: One of the things that also frequently attract people�s attention

  • is what a great trader Warren Buffet is. In fact, I know that youve been critical of

  • the Black Swan Theory which tries to discourage people from looking at these huge aberrations.

  • The black swan theory is there�s going to be someone who is the best and then we always

  • think that there�s something really magical about that investor. You didn�t seem to

  • see it the same way as the economist Nassim Taleb?

  • James Owen Weatherall: There are few things that I�m critical about with Taleb. He has

  • the idea that because of black swan, because of extreme events that are far outside of

  • expectations, the tools and methods that we use in mathematical finance, basically mathematics

  • period, can�t help us understand market. I think that�s pretty short-sided and in

  • fact, many of the ideas that he has developed are based on the work of a mathematician and

  • physicist named Benoit Mandelbrot how introduced the tools that one would need in order to

  • think about these sorts of extreme situations.

  • Douglas Goldstein: Is this model constantly changing? Is it worthwhile to bring more physicists

  • into the fray to try and study the events of Wall Street?

  • James Owen Weatherall: It seems to me that the answer is yes. One thing that we should

  • never do is make the mistake that models that are working pretty well right now are somehow

  • the absolute truth. Models are certain kinds of approximate representations. They are useful

  • to us in all sorts of ways. They can make predictions about how markets are going to

  • change. They can tell us what kinds of relationships we should expect between derivative prices

  • and other prices. As I said before, they are based on assumptions that are usually at best

  • approximate and sometimes quite radically false.

  • Douglas Goldstein: When someone comes up with a theory or a model, it will work for a certain

  • period of time perhaps but then it loses its magic touch?

  • James Owen Weatherall: That can happen or alternatively, it could work under some general

  • condition. A good example was a model that failed in 2007 and 2008 because housing markets

  • began to decline. You can have a model that works whenever housing pricing are going up

  • and doesn�t work when housing prices are going down because there�s a kind of implicit

  • assumption on how the model is built. So it�s not that it�s going to lose its magic touch

  • forever, it�s just that youre misapplying it and if you apply it under circumstances

  • when housing prices are declining.

  • I think one of the things that people with backgrounds in fields like physics and math

  • can continue to do is develop new models and also question the assumptions underlying current

  • models. It�s not clear that people who are using models in markets, practitioners and

  • investors, have the time or the background or the skills to figure out whether or not

  • the model they are using is the perfect one for right now. Someone needs to be doing that.

  • In some sense, this is where I agree with Taleb that if you don�t do things like that

  • and if you are too complaisant about the models that you use about the mathematics that you

  • use, youre creating enormous risks.

  • Douglas Goldstein: How can people follow your work or research?

  • James Owen Weatherall: The book is called the Physics of Wall Street and it�s available

  • online. It is published by Houghton Mifflin Harcourt. My website is www.jamesowenweatherall.com.

  • Douglas Goldstein, CFP�, is the director of Profile Investment Services and the host

  • of the Goldstein on Gelt radio show (Monday nights at 7:00 PM on www.israelnationalradio.com.

  • He is a licensed financial professional both in the U.S. and Israel. Securities offered

  • through Portfolio Resources Group, Inc., Member FINRA, SIPC, MSRB, NFA, SIFMA. Accounts carried

  • by National Financial Services LLC. Member NYSE/SIPC, a Fidelity Investments company.

  • His book Building Wealth in Israel is available in bookstores, on the web, or can be ordered

  • at: www.profile-financial.com (02) 624-2788 or (03) 524-0942.

  • Disclaimer: This document is a transcription and/or an educational article. While it is

  • believed to be current and accurate, divergence from the original is to be expected. The original

  • podcast can be heard at https://sites.google.com/site/goldsteinradioshows/. All information on this website is purely

  • information and should not be used as the sole basis for making financial decisions.

  • The opinions rendered herein are those of the guests, and not necessarily those of Douglas

  • Goldstein, Profile Investment Services, Ltd., or Israel National News. Readers should consult

  • with a professional financial advisor before making any financial decisions. Please see

  • the complete disclaimer at https://sites.google.com/site/goldsteinradioshows/.

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詹姆斯-歐文-韋瑟爾--華爾街的物理學--採訪--戈德斯坦在Gelt上--2013年6月。 (James Owen Weatherall-The Physics of Wall Street - interview - Goldstein on Gelt - June 2013)

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    李掌櫃 發佈於 2021 年 01 月 14 日
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