Market Inefficiency

Brunnermeier, Markus K. “Information Leakage and Market Efficiency”. Review of Financial Studies 18 (2005): , 18, 417-457. Print.Abstract

This article analyzes the effects of information leakage on trading behavior and market efficiency. A trader who receives a noisy signal about a forthcoming public announcement can exploit it twice. First, when he receives it, and second, after the public announcement since he knows best the extent to which his information is already reflected in the pre-announcement price. Given his information he expects the price to overshoot and intends to partially revert his trade. While information leakage makes the price process more informative in the short-run, it reduces its informativeness in the long-run. The analysis supports Securities and Exchange Commission's Regulation Fair Disclosure.


Information leakage lowers market efficiency in the long run.

Brunnermeier, Markus K, and Lasse Heje Pedersen. “Predatory Trading”. The Journal of Finance 60 (2005): , 60, 1825-1863. Print.Abstract

This paper studies predatory trading, trading that induces and/or exploits the need of other investors to reduce their positions. We show that if one trader needs to sell, others also sell and subsequently buy back the asset. This leads to price overshooting and a reduced liquidation value for the distressed trader. Hence, the market is illiquid when liquidity is most needed. Further, a trader profits from triggering another trader's crisis, and the crisis can spill over across traders and across markets.

predatory_trading.pdf predatory_trading_slides.pdf

When a large trader has to liquidate, "predators" also sell and withdraw liquidity. This leads to price overshooting and systemic risk.

Brunnermeier, Markus K, and Stefan Nagel. “Hedge Funds and the Technology Bubble”. The Journal of Finance 59 (2004): , 59, 2013-2040. Print.Abstract

This paper documents that hedge funds did not exert a correcting force on stock prices during the technology bubble. Instead, they were heavily invested in technology stocks. This does not seem to be the result of unawareness of the bubble: Hedge funds captured the upturn, but, by reducing their positions in stocks that were about to decline, avoided much of the downturn. Our findings question the efficient markets notion that rational speculators always stabilize prices. They are consistent with models in which rational investors may prefer to ride bubbles because of predictable investor sentiment and limits to arbitrage.

hedgefunds_bubble.pdf hedgefunds_bubble_slides.pdf

Hedge funds were riding the technology bubble instead of exerting a price correcting force.

Abreu, Dilip, and Markus K Brunnermeier. “Synchronization risk and delayed arbitrage”. Journal of Financial Economics 66 (2002): , 66, 341-360. Print.Abstract

We argue that arbitrage is limited if rational traders face uncertainty about when their peers will exploit a common arbitrage opportunity. This synchronization risk—which is distinct from noise trader risk and fundamental risk—arises in our model because arbitrageurs become sequentially aware of mispricing and they incur holding costs. We show that rational arbitrageurs “time the market” rather than correct mispricing right away. This leads to delayed arbitrage. The analysis suggests that behavioral influences on prices are resistant to arbitrage in the short and intermediate run.


Models the Wile E. Coyote effect, since synchronization risk leads to market timing by arbitrageurs and delays arbitrage.