Rajiv Sethi Mon 2010-09-20 10:04 EDT
An Extreme Version of a Routine Event
The flash crash of May 6 has generally been viewed as a pathological event, unprecedented in history and unlikely to be repeated in the foreseeable future...far from being a pathological event, the flash crash was simply a very extreme version of a relatively routine occurrence...the flash crash can provide us with insights into the more general dynamics of prices in speculative asset markets...The crash revealed with incredible clarity how (as James Tobin observed a long time ago) markets can satisfy information arbitrage efficiency while failing to satisfy fundamental valuation efficiency...Aside from scale and speed, one major difference between the flash crash and its more routine predecessors was the unprecedented cancellation of trades...this was a mistake: losses from trading provide the only mechanism that currently keeps the proliferation of destabilizing strategies in check...