Unveiling the Identity of PIN from the Flash Crash: Illiquidity or Information Asymmetry?
University of Michigan at Ann Arbor
August 1, 2011
This paper extends the original PIN framework to explicitly allow for the coexistence of liquidity shocks and fundamental news, both of which can lead to order imbalances. The pseudo market makers submit contrarian orders in the event of liquidity shocks and thus move the stock prices back to the fundamental level. Consequently, the conventional PIN measure consists of one component driven by the informed traders who receive the fundamental news and another component due to pseudo market makers who arrive upon liquidity shocks. During the flash crash on May 6, 2010, there is a nearly ten-fold market-wide increase in the illiquidity component of PIN but there is a lack of uniform increase in the information asymmetry component, based on the estimation of the extended PIN model for common stocks listed on NYSE and AMEX. In contrast, the original PIN model disallows liquidity shocks and thus overestimates the extent of asymmetric information. In addition to introducing a conceptually more pure measure of asymmetric information than that is previously available, this paper also contributes to the literature through methodological improvements to the PIN estimation and provides the recipe to eradicate the numerical overflow and underflow problems and impute the daily PIN series from repeated estimations of quarterly PINs.
Number of Pages in PDF File: 40
Keywords: Probability of Informed Trading (PIN), Information Asymmetry, Flash Crash, Floating Point Overflow, Daily PIN Series
JEL Classification: G10, G14
Date posted: October 26, 2010 ; Last revised: August 4, 2011