
Black Swans Fat Tails and Financial Markets
The mathematical models used by hedge funds, money center banks, and big investment banks, like even the smart boys at Goldman Sacks, seem to have the evaluation of risks and the frequency at which “rare” statistically almost impossible to occur events actually do occur all wrong.
A black swan is an event that is truly disastrous when it does occur but fortunately, according to the investment models, will occur very rarely. So rarely, in fact, that it makes no sense to worry about it. A recent black swan that has hit the stock markets of the world squarely between the eyes and is still flying wildly about, is the subprime mortgage market meltdown.
Mathematical models discounted the percentage of mortgages that could go bad to such a low number that the effect of just a few going bad from time to time was expected to have little effect on the overall mortgage portfolio. Obviously, given the events of the past year, something very wrong was build into the mathematical models.
A fat tail is an event or serious of events that are considered to be well outside the range of what is consider normal. A bell curve is usually used to demonstrate the distribution of events. If we plot events to a graph, since normal events occur most of the time the largest number of events would be as expected , at or very near the center of the curve.
Events which occur slightly less than normal would be plotted a bit further away from the center, until finally rare events would be plotted at the far end of the graph. Once plotted to a chart the graph would have the shape of a bell, thus the name bell curve.
The financial house statisticians placed in their models certain events likelihood of occurring way at the end of the bell curve. Often so many standard deviations away from the norm that the events were expected to occur once in a hundred thousand years, if at all. Imagine their surprise and disbelieve when a number of these events occurred one after the other giving their bell curve an unexpected fat tail.
What when wrong? How could so many very smart people come up with investment risk models that have proven to be so mismatched with real world events? How could have so many of Wall Streets brightest con men, eeerrrrr, sorry, financial managers, chairman, and CEO’s, expand their businesses into such risky areas as repackaging loans make to people who don’t have the ability to repay into investment packages that carry a AAA rating? How indeed?
A good summary of the black swan and fat tail problem is this quote: “It ain’t what You Don‘t know that gets you into trouble. It’s what you know for sure that just ain’t so” (Mark Twain?).
The mathematical models may work fine in a theoretical world. In that world economists, mathematicians, and investment bank analysis, buy into the theory that human beings are rational creatures and will always take actions that are in their own self interests. They also buy into the nonsense that markets are always right, that the current price for a security must be the correct price because at that point in time the market says so.
Unfortunately human beings are often not rational at all. They have a marked tendency to follow each other around. The herd instinct is strong. Humans can stampede one after the other in one direction and then let’s say a black swan event occurs, like two hijacked planes slamming into the World Trade center twin towers, and almost immediately the herd reverses course and charges off in the opposite direction.
Alas, the mathematical models used by the big boys to identify and rate risk just can’t get a grip on human emotions and behavior. Fear can turn into greed and greed into fear quicker than you can say buy or sell. In financial markets, be they stocks, bonds, commodities, or forex, the effects of fear are often multiplied many times over because of the financial leverage that many investors use in structuring their investments.
Under extreme stress black swans and fat tails seem to flourish. Events that according to the models should only happen once in a million years may happen several times in one week. Perhaps the big smart boys aren’t nearly as smart as they think they are. Do they really deserve to pay themselves millions of dollars a year in bonuses on top of multi million dollar salaries? Is this what late stage rape and pillage the average investor capitalism has come to?
About the Author
Gerald “Taipan” Greene is a retired forex trader and portfolio manager who worked in Asia for over 20 years. The nickname was acquired in Hong Kong and is now used for a number of financial, political, and Internet business related blogs. One of them is at Bold Messenger
Slash with Michael Jackson 1991 VERY RARE Black or White MTV 10th anniversary
|
|
Libbey Polaris Drinking Glasses and Tumblers, Set of 16 $26.99 16-piece set of drinking glasses with heavy, 1-inch-thick rounded bases that impart substance and stabilityWith 16 glasses total, the set includes eight tumblers and eight glassesThe glasses measure 2-3/4 by 2-3/4 by 6-1/2 inches and hold 16-1/4 ounces; tumblers are 3 by 3 by 4 inches and hold 12-1/4 ouncesLayers beautifully with a variety of dinnerware and table settings; crystal-clear glass cons… |
|
|
Disc Magnet is only 1/2 in Diameter But Has Terrific Holding Power (Pkg/200) $17.50 These 1/2″ diameter flat magnets can be glued to any surface. Strong, permanent magnet has holding power on either side. A popular size for many craft applications, these inexpensive disc magnets can be used in a variety of ways. They have the perfect amount of magnetism, neither too strong nor so weak that they wont stay in place. They make great magnet backs for custom designed refrigerator atta… |
|
|
Royal Albert 100 Years of Royal Albert Teacups and Saucers, Set of 5, 1900-1940 $202.98 As it embarks on a new century of fine china design, Royal Albert honors the artistic achievements of the one it has so faithfully chronicled with this stunning 100 Years of Royal Albert tribute collection. Employing classic shapes and delicate floral motifs, the 10-part series, which includes teaware, figurines, and brooches, recalls major British historical events and style trends from each deca… |
|
|
Abbey Road (Remastered) $9.94 BEATLES THE ABBEY ROAD (EDICION LIMITADA)… |
|
|
Sublime $7.89 For all his tattoos and bulked-up frat-boy persona, singer Bradley Nowell had real soul, which made his fatal heroin overdose even more tragic. There’s more to this Long Beach, California, trio’s debut, released shortly after Nowell’s death in 1996, than white suburban punks imitating Jamaican ska music. The band comes up with great songs, notably the catchy MTV hit “What I Got”; spooky dub-reggae… |
|
|
Between the Devil & The Deep Blue Sea $6.59 All products are BRAND NEW and factory sealed. Fast shipping and 100% Satisfaction Guaranteed…. |
|
|
Snow White and the Seven Dwarfs (Walt Disney’s Masterpiece) [VHS] $0.01 One of the brightest nuggets from Disney’s golden age, this 1937 film is almost dizzying in its meticulous construction of an enchanted world, with scores of major and minor characters (including fauna and fowl), each with a distinct identity. When you watch Snow White’s intricate, graceful movements of fingers, arms, and head all in one shot, it is not the technical brilliance of Disney’s artists… |
|
|
Fantasia (Walt Disney’s Masterpiece) [VHS] $2.97 Along with Fantasia and Fantasia 2000, the anthology set contains a third disc that examines a segment of both movies in detail. Each segment has an introduction that has experts (including Leonard Maltin), producer Roy E. Disney, or the animators setting up the piece’s history. Notes on the music and dozens of design photos are included on all the segments, although others offer more intrig… |
|
|
Sega Dreamcast Sports Pack This is a rare BLACK SEGA SPORTS DREAMCAST CONSOLE w/ Matching controller….. |
|
|
CH Hanson 03040 Magnetic Stud Finder $5.22 The Stud 4 Sure is a stud finder that uses powerful rare earth magnets to pinpoint the exact location of screws or nails in a stud. The tool doesn’t require batteries and never needs calibration. By keeping the tool free of moving or electronic parts, the Stud 4 Sure is easy to use and fits easily into any tool pouch. Just place the stud finder on the wall and sweep in an “S” pattern to loca… |
Related Articles
No user responded in this post
Leave A Reply