May

28

 To what extent can Pascal's principle where a change in pressure is transmitted undiminished to all parts of an enclosed liquid or gas system, whereby a small change in force on a narrow area can move a much larger force on a larger area as used in car lifts or construction machinery, be applied to markets in certain situations? Is this a useful question?

Stefan Jovanovich writes: 

The Chair has asked a question that I cannot answer so I will add to my stack of irrelevant comments. What is called the Industrial Revolution was neither. Metal working and large scale enterprise were not new things. The Arsenal at Venice and the Royal Navy's yards with Brunel Sr.'s block carving automatic lathe did not need the "invention" of the steam engine. It was the discovery and application of the paradoxes of fluid dynamics that created our modern world — first steam, then gases and liquids generally.

Gary Phillips writes: 

Mauboussin likes to talk about the market as a complex adaptive system and critical points where large scale reactions are the result of small scale perturbations, the implication being that causality can be difficult to identify because it is often very subtle.

Traders tend to focus on multiple and ubiquitous agents that may not drive price, but do support their directional bias, while ignoring potential outcomes with low probability that may be driven by hidden or obscure agents. Same with systems with too many degrees of freedom and over fitting.

Gary Rogan writes: 

I often think of the market as a Pascal system or a school of fish. How do all the stocks know to move the similar direction?

Ralph Vince writes:

In the context of fluid dynamics, Gary's question leads to the (near inescapable) conclusion that the movement of stocks prices, in this context (with an isomorphism to 3D space of the varioius stocks) is characteristic of the flow WITHIN the de/compressing cylinder itself, under varying states of compression at varying times.

A study of hydraulic flows would show that fluid flow within the cylinder itself is not uniform, and is also a function of various degrees of pressure.

From this we could create such a model.

Gary Rogan responds: 

It is kind of like that, but it's almost like there are local agitators within the cylinder. This morning provides a perfect example that I can see in my own stocks. Some joint venture news in MDLZ, one of the Kraft spinoffs has provided positive agitation to the food stocks, and more so to the specifically beverage stocks, and less so to the consumer non-durable stocks. This agitation is somewhat sticky in that when the market first rose for whatever reasons and then fell likely on Yellen's remarks, these stocks seemingly have experience a smaller sensitivity to the market had the important news not occurred. It's like a decompressing cylinder with small local explosions/collapses.

Ralph Vince adds: 

 Matter in the expanding (i.e. decompressing) universe may be a better model?

But it still boils down to a feed back loop where the output of one becomes the input for the next ( in one case amplifying and in the other dampening).

Gary Rogan writes: 

That's an excellent analogy and something I've been reading a lot about! It's not perfect but likely productive.

Immediately after the Big Bang the small world was pretty uniform. But then quantum uncertainty fluctuations have added a small pattern to the Universe that was the progenitor of what we all see today. In addition sound-like wave resonated within the Universe leading to the spectrum we still see in the microwave radiation today. Gravity has dramatically amplified the initial quantum fluctuation leading to the truly observable local pattern of galaxies, stars, and planets. And of course all the following star formations, collapses, and explosions created all the heavy elements as well reshaped the local structure of galaxies. Plus there is all the dark matter and dark energy (dark pools?) that exert gravitational and expansionary forces that can only be guessed at by their effect.

Craig Mee writes:

From the back benches, I think the problem may lie in measuring the change in volatility, since under no news conditions, the environment may be ideal, for example, after news releases in Europe mid morning before the states come in. After that though, it may be difficult to separate cause from effect. 

Jim Sogi writes: 

Might a small amount of money pouring into something like gold or oil or wheat move the entire market? The canary principle might be at work rather than Pascal's causal function, and there may be a lag, complicating the relationship.

anonymous writes: 

 The use of finite-volume methods in sell-side modelling suggests it is a useful question. Market cap is a "squishy" concept of volume, as it can change when prices rise and fall. Book value is less squishy but still far from rigid.

Imagine a directed graph of trade flows among several companies, forming a trade network. Suppose there is a bottleneck somewhere. Destroying this link might be more disruptive than destroying other links.

My father used to talk about one of his coworkers who whirled about his organisation with fingers in every pot. This individual did much more than his job description suggested. When he left the organisation many projects across departments floundered.

The Allies' North African campaign of WW2 was meant to attack a "pressure point": Rommel's petrol supplies. Paraphrasing ER: "The bravest man can do nothing without guns, the guns can do nothing without ammunition, and neither guns nor ammunition are mobile without petrol."

I would also use the metaphor of joint-locks in jiu jitsu. Consider the manifold of configurations of your opponent's feet, knees, hips, shoulders, elbows, wrists, fingers. Applying pressure (vector) to the wrist and fingers in most of these configurations will not move the opponent's feet or hips. Joint locks find the configurations where a small force in precisely the right direction will cause the opponent's feet and hips to move a lot.

Saving the geekiest example for last: in George Lucas' fantasy world, certain Jedi Consulars are able to, with sufficient meditation and magic, see "shatter points" in a situation–precisely the kinds of vulnerabilities that will spread and multiply force to a wider area.


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