Wednesday, October 29, 2008

Event-Driven Financial Catastrophe

Is Complex Event Processing (CEP) part of the problem or part of the solution?

On the one hand, apparently knowledgeable financial journalists tell us that automatic and globalized trading has contributed to an unprecedented level of global volatility. For example, the dramatic rise in Volkswagen shareprice yesterday appears to have been amplified by computer programs automatically reacting to a small price rise by attempting to buy shares (in order to unwind positions resulting from earlier short-selling by hedge funds), thus converting a small price rise into an extremely large one.

On the other hand, I am constantly seeing claims from vendors that their CEP products contain ways of dealing with market volatility, as if the volatility is merely caused by the failure of humans to react as quickly and as intelligently as their software.

But what I don't see in this kind of CEP material is a picture of how the whole system works: an evidence-based explanation as to what causes volatility, and what are the overall consequences of a particular kind of intervention. That kind of whole-system thinking is surely a key responsibility of the architect. By refusing to pay attention to the whole system, this kind of CEP discourse is almost anti-architectural. That's why I think we should call it JBOCE.

(Of course, a lot of so-called architects aren't very good at that kind of whole-system thinking, and indulge in what Nick Malik calls Bizarre Functional Decomposition, but that's another story.)

Speaking for one of the CEP vendors (Streambase), Mark Palmer (EDA and CEP: Where's the Beef?) protests against recent posts by Jack van Hoof (EDA versus CEP, Again...) and Joe McKendrick (Why 'Event Driven Architecture' is more than Complex Event Processing).

But I think the problem identified by Jack and Joe is not that vendors are asserting that CEP and EDA are the same thing. I am sure all the vendors, including Mark, can point to technical material that explains what these terms really mean. The problem is that the terms are being used in ordinary marketing material as if they were interchangeable - in other words, the vendors are not putting enough emphasis on the practical differences between CEP and EDA. I think the spate of claims about CEP "solving" market volatility is further evidence of this.


Hans said...

Unfortunately, there is a known relationship where firms trying to reduce their own volatility end up increasing the short term market volatility. It can be thought of simplistically as the prisoner's dilemma, but with more rules.

Should a CEP vendor provide a better alternative, they can probably expect to hear from the Nobel Foundation.

Richard Veryard said...

Of course it is conceivable that firm might manage to reduce its own volatility using CEP, while increasing overall volatility - thus the solution would be environmentally counter-productive as you say. But I haven't seen any evidence that CEP even achieves that much. Without a proper architectural framework, we simply don't have a clue what effect speeding things up will have.

Hans said...

Hmm. What evidence would you be looking for about the capabilities of CEP?

If you are talking about an architectural framework for electronic trading, that definitely exists but AFAIK not for free on the web...

Richard Veryard said...

Hi Hans. When you say "architectural framework", we may not be talking about the same thing. But I'd be happy to review it under NDA.