The first essay examines the events of May 6, 2010: the ``Flash Crash". The Flash Crash, a brief period of extreme market volatility on May 6, 2010 raised questions about the current structure of the U.S. financial markets. Audit-trail data from U.S. Commodity Futures Trading Commission (CFTC)...

This paper investigates the impact of exchange-traded funds (ETFs) on the liquidity of their underlying stockholdings. Using a difference-in-differences methodology for large changes in the index weights of stocks in the S&P 500 and NASDAQ 100 indexes, we find that increases in ETF ownership are...

Using a database of news articles from Thomson Reuters for 2003-2008, we investigate how the arrival rate of news articles mentioning an individual stock varies with the level of trading activity in that stock. Defining trading activity W as the product of dollar volume and volatility, we...

Market liquidity is expected to facilitate arbitrage, which in turn should affect the liquidity of the assets traded by arbitrageurs. We study this relationship using a unique dataset of equity and bond ETFs compiled from big trade-level data. We find that liquidity is an important determinant...

We study intraday market intermediation in an electronic market before and during a period of large and temporary selling pressure. On May 6, 2010, U.S. financial markets experienced a systemic intraday event - the Flash Crash - where a large automated selling program was rapidly executed in the...

This paper investigates the impact of exchange-traded funds (ETFs) on the liquidity of their underlying stockholdings. Using a difference-in-differences methodology for large changes in the index weights of stocks in the S&P 500 and NASDAQ 100 indexes, we find that increases in ETF ownership are...

The Flash Crash of May 6, 2010, shook the confidence of market participants and raised questions about the market structure of electronic markets. In these markets, intraday intermediation has been increasingly provided by market participants without formal obligations to do so. We examine...

This paper studies invariance relationships in tick-by-tick transaction data in the U.S. stock market. Over 1993-2001, monthly regression coefficients of the log of the trade arrival rate on the log of trading activity have an almost constant value of 0.666, close to the value of 2/3 predicted...

This paper studies Leveraged and Inverse Exchange Traded Funds (LETFs) from a financial stability perspective. Mechanical positive-feedback rebalancing of LETFs resembles the portfolio insurance strategies, which contributed to the stock market crash of October 19, 1987 (Brady Report, 1988). I...