News Blog

News Blog


Mathematicians predicted stock market volatility years ago

Crash, crash. Doom, doom. Panic on the Street. Wall Street yesterday suffered its worst decline since the Sept. 11 terrorist attacks – and the free fall suggests it may be time to consider burying the family stash of Krugerrands under the rose garden or tool shed.

The list of Chicken Little events was long:  investment house Lehman’s bankruptcy, the capital crunch for mega-insurer AIG, the sale of Merrill Lynch to Bank of America. But Stormy Monday (a weather system that appears to be carrying over to be lingering) probably came as no surprise to a cadre of mathematicians who specialize in surveying the dynamics of markets.

One of those long-time market watchers is fractal pioneer Benoit Mandelbrot. In 1999, Scientific American published an article by Mandelbrot that showed how fractal geometry can model market volatility, while revealing the intrinsic deficiencies of a cornerstone of finance called modern portfolio theory (for which there has been awarded more than one Nobel Prize in Economics).

Mandelbrot, 83, contends that portfolio theory, which tries to maximize return for a given level of risk, treats extreme events (like, say, yesterday's market shockers) with “benign neglect: it regards large market shifts as too unlikely to matter or as impossible to take into account.” The faulty assumption of modern portfolio theorists, in Mandelbrot’s view, is that price changes do not drift far from the mean when observing daily ups and downs—so extreme events are exceedingly rare. “Typhoons, in effect, are defined out of existence,” he wrote.

In place of modern portfolio theory’s reliance on the canonical Bell Curve, Mandelbrot drags in (surprise!) the fractal. A fractal is a geometric shape that can be divvied up into parts, each of which is a Mini-Me facsimile of the whole. If you look closely enough, you can see fractals everywhere. Besides monotonous screen savers, fractal patterns describe the distribution of galaxies and the shape of coastlines. Mandelbrot devised so-called multi-fractal generators that can use historical market data to simulate alternative scenarios of where stocks or other securities might be headed.

The experience of editing Mandelbrot a decade ago was both fun and exasperating. Trying to translate the complexities of multifractals into a finished text demanded a lot of neural gear grinding to say the least.
Dealing with this renowned creator of the Mandelbrot set was another challenge.

The conversation always seemed to drift back to his other favorite subject: how the rest of the world  did not appreciate the  value of his work. At one point, I asked  whether he believed he should receive a Nobel (highly unlikely for a mathematician).  One does not discuss such things, he said, as if it might jinx his chances.

We received a stack of letters and e-mails after the article was published, including a bundle from adherents of  the so-called Elliott Wave Theory alleging that Mandelbrot had lifted his ideas (on the multifractal nature of markets) from the work of Ralph Nelson Elliott in the 1930s. An insulted Mandelbrot dismissed the charges with withering disdain: “The idea is ancient, but his use and mine stand in absolute contrast,” he responded in the mag's letters column.

Perhaps the most telling criticism of Mandelbrot’s work comes from the markets themselves. In the decade or so since his article was published, the use of multifractal market analysis is still largely an academic endeavor. But Mandelbrot should not be judged too harshly. Multifractals may not be in routine use on the trading floors. But Mandelbrot’s work on market extremes has served to broadcast to the Street a notion that has been known forever on the street: Yes, Virginia, sh*t really does happen.

Photo of Benoit Mandelbrot, 2007, by Rama

 

 

 

 

Tags: wall street, mandelbrot, stock market
More News Blog: Next: Web surfer, he's not, but BlackBerry is John McCain's "miracle," aide says Previous: Better late than never? Clergyman says church owes Darwin an apology

15 Comments

Add Comment
View
  1. 1. scientificamericanaism 11:09 AM 9/23/08

    Mandelbrot's multi-fractal generator brings up many interesting questions and ideas. As Mandelbrot attempted to simulate market patterns, Mandelbrot resorted to adding a speed value to his multi-fractals in order to make the charts more realistic. The speed value allowed certain parts of the multi-fractal to copy smaller versions of itself within itself at different rates/ speeds/ frequency than other parts of the non-speed affected areas of the larger fractal. Even with the speed variable, multi-fractals are still unable to reproduce realistic market charts. But, perhaps different parts of the fractal contain different speed values...

    Reply | Report Abuse | Link to this
  2. 2. benvoxley 12:58 PM 9/30/08

    We knew this was coming. Please watch this video: http://www.youtube.com/watch?v=Yul0nnilILw

    Reply | Report Abuse | Link to this
  3. 3. eco-steve 05:14 PM 2/3/09

    Perhaps I am stupid, but I fail to see how Markey graphs relate to fractal theory. To obtain a fractal pattern write a very concise algorythm which is self-referential and recursive. Market curves are governed by Chaos Theory, as there are too many unknowns for initial values to be significant. Introduce randomness to a fractal curve and you get nonsense on the screen. Fractals are totally predictable, even if writing them is a logical nightmare.

    Reply | Report Abuse | Link to this
  4. 4. nimajha 09:24 AM 7/15/09

    Do you think it is possible?

    This guy Anthony claims to have a formula
    to turn&

    $1000 into $1 million in roughly 5 years.
    Or $2000 into $1.7 million in just 1.9 years!

    I'm not sure...
    But this guy shows you a video where
    he is actually doing it.

    And he does it so effortlessly and explains
    it all, as he goes along.

    Watch this video and decide yourself&

    http://www.2stocktrading.com/offer5.html

    This type of quick cash injection...
    Should be ILLEGAL!

    Reply | Report Abuse | Link to this
  5. 5. pennystocks 02:40 AM 7/1/10

    Anyone who is an investor or who plans to invest some of their money in the market always has one question on their mind: What are the good <a href="http://www.stocktrains.com"> Penny Stocks </a>
    out there? You see people making lots of cash by putting their money into the companies they believe in, but not all of these companies are publicly traded on the New York Stock Exchange or on NASDAQ.

    Reply | Report Abuse | Link to this
  6. 6. markettips1 in reply to eco-steve 08:06 AM 7/19/10



    Investing is a quite a complex exercise. But when it comes to Indian stock market the basic principles, they are amazingly simple. Anyone can become good investor and reach your goals just by following those simple and easy rules. Here is the list of few <a href="http://www.sharetipsexpert.com">Indian stock market tips</a> rules for making investment in mutual funds:
    Be a long-term investor: Start Early: Know yourself and then What You Are Buying: Be A Disciplined Investor:

    Alternately people may also trade in <a href="http://www.sharetipsexpert.com/Commodity_trading_tips.aspx">MCX tips</a> . Client may also trade in nifty and make good money from free <a href="http://www.sharetipsexpert.com/news1.aspx?id=24">nifty trading tips</a> available online.

    Reply | Report Abuse | Link to this
  7. 7. RBIDDLE 10:13 PM 7/21/10

    DOES ANYONE KNOW OF AN ARTICLE ABOUT TRADING THE MARKET VIA FIBONACCI THAT I FOUND IN SCIENTIFIC AMERICAN, I THINK, BACK IN THE MID 80S PRIOR TO THE CRASH IN '87?

    Reply | Report Abuse | Link to this
  8. 8. mariasharapova844 05:24 AM 8/4/10

    <a href="http://www.livestockauction.org" rel="dofollow">Stock Chart</a>
    I am stupid, but I fail to see how Markey graphs relate to fractal theory

    Reply | Report Abuse | Link to this
  9. 9. robbinsmith 09:58 PM 8/5/10

    <a href="http://www.forexaddicts.com/" rel="dofollow">Stock Analysis</a>

    Reply | Report Abuse | Link to this
  10. 10. altondelmote 12:45 AM 10/21/10

    The Market was hemorrhaging like a stuck pig, and nobody had a clue how to stop it, resulting in complete financial free-fall.

    Thanks
    www.pennyinvest.com

    Reply | Report Abuse | Link to this
  11. 11. sharetipsinfo 05:29 AM 11/15/10

    Hi,
    Seems like it’s a nice blog. So let us also add something useful in it. <a href="http://www.sharetipsinfo.com" title="Trading"> Trading </a>in volatile market can be very fruitful also if we follow technical levels closely. It’s a common saying that stock market can change fortune in either way. But now the question is how to earn money from the Indian stock market.

    Traders are advised to strictly follow technical analyses and investors can follow fundamental analysis. Many analysts say it’s not wise to follow technical and fundamental analysis together. But we say what the problem is if one does so? As more knowledge will add up things will not have any negative impact.

    Regards
    . <a href="http://www.sharetipsinfo.com" title="Sharetipsinfo Team">Sharetipsinfo Team</a>

    Reply | Report Abuse | Link to this
  12. 12. kanikapatel11 08:01 AM 7/4/11

    hi Gary Stix, Seems like it’s a nice blog. So let us also add something useful in it. Trading in volatile market can be very fruitful also if we follow technical levels closely. It’s a common saying that stock market can change fortune in either way. But now the question is how to earn money from the Indian stock market.

    Traders are advised to strictly follow technical analyses and investors can follow fundamental analysis. Many analysts say it’s not wise to follow technical and fundamental analysis together. But we say what the problem is if one does so? As more knowledge will add up things will not have any negative impact. REgards: http://www.iasr.in/

    Reply | Report Abuse | Link to this
  13. 13. devangvisaria 05:53 AM 8/26/11

    You made some decent points there. I looked on the internet for the issue and found most individuals will go along with with your website.

    Thanks & regards,
    http://www.devangvisaria.com

    Reply | Report Abuse | Link to this
  14. 14. robertdavis 05:46 AM 9/3/11

    Thanks for this good one.....


    http://www.chasingbeta.com/

    Reply | Report Abuse | Link to this
  15. 15. GilBurt 06:08 AM 11/1/11

    The basic principles of Indian stock market is very simple. Anyone can become good investor and reach your goals just following this rules.

    http://www.otcmarketalerts.com/

    Reply | Report Abuse | Link to this
Leave this field empty

Add a Comment

You must sign in or register as a ScientificAmerican.com member to submit a comment.
Click one of the buttons below to register using an existing Social Account.

More from Scientific American

See what we're tweeting about

Scientific American Editors

More »

Free Newsletters


Get the best from Scientific American in your inbox

Solve Innovation Challenges

Powered By: Innocentive

  SA Digital
  SA Digital

Science Jobs of the Week

Email this Article

Mathematicians predicted stock market volatility years ago: Scientific American Blog

X
Scientific American Magazine

Subscribe Today

Save 66% off the cover price and get a free gift!

Learn More >>

X

Please Log In

Forgot: Password

X

Account Linking

Welcome, . Do you have an existing ScientificAmerican.com account?

Yes, please link my existing account with for quick, secure access.



Forgot Password?

No, I would like to create a new account with my profile information.

Create Account
X

Report Abuse

Are you sure?

X

Institutional Access

It has been identified that the institution you are trying to access this article from has institutional site license access to Scientific American on nature.com. To access this article in its entirety through site license access, click below.

Site license access
X

Error

X

Share this Article

X

About the Bering in Mind Blog

In this column presented by Scientific American Mind magazine, research psychologist Jesse Bering of Queen's University Belfast ponders some of the more obscure aspects of everyday human behavior. Ever wonder why yawning is contagious, why we point with our index fingers instead of our thumbs or whether being breastfed as an infant influences your sexual preferences as an adult? Get a closer look at the latest data as "Bering in Mind" tackles these and other quirky questions about human nature. Sign up for the RSS feed or friend Dr. Bering on Facebook and never miss an installment again.

X

About the Cross-check Blog

Every week, John Horgan takes a puckish, provocative look at breaking science. A former staff writer at Scientific American, he is the author of several books—most notably, The End of Science: Facing the Limits of Knowledge in the Twilight of the Scientific Age. He currently directs the Center for Science Writings at Stevens Institute of Technology. He lives in New York State's Hudson Highlands, where he plays ice hockey each winter to hone his cross-checking skills.

X

Expeditions Blog

Ever wonder what it's really like to be working in Antarctica or collecting core samples from the middle of the Pacific Ocean? Get a first-hand feel for scientific exploration by following the blog posts of researchers out in the field.

X

About the Extinction Countdown Blog

Several times a week, John Platt shines a light on endangered species from all over the globe, exploring not just why they are dying out but also what's being done to rescue them from oblivion. From unusual or little-known organisms like the giant spitting earthworm and the stinking hawk's-beard to popular favorites like cheetahs and koalas, Platt, a journalist specializing in environmental issues and technology, does his part to slow the countdown.

X

About the Guest Blog

The editors of Scientific American regularly encounter perspectives on science and technology that we believe our readers would find thought-provoking, fascinating, debatable and challenging. The guest blog is a forum for such opinions. The views expressed belong to the author and are not necessarily shared by Scientific American.

X

About the Solar at Home Blog

Follow Scientific American editor George Musser as he installs--or tries to install--solar photovoltaic panels on the roof of his suburban New Jersey home. You'll learn the literal nuts and bolts of going green with the sun and get energy-saving tips even if you aren't putting up panels.

Write to us with tips or comments at blog@sciam.com and follow us on Twitter: http://twitter.com/sciam.

X