We show that High Frequency Traders (HFTs) are not beneficial to the stock market during flash crashes. They actually consume liquidity when it is most needed, even when they are rewarded by the exchange to provide immediacy. The behavior of HFTs exacerbate the transient price impact, unrelated...

This contribution addresses the impact of high-frequency electronic liquidity provision strategies on financial markets' intraday dynamics, by evaluating the interaction between multiple trading strategies within a computer laboratory, i.e. an artificial stock market. Initially, a realistic...

We use the introduction of a financial transaction tax (FTT) in France in 2012 to test competing theories on its impact. We find no support for the idea that an FTT improves market quality by affecting the composition of trading volume. Instead, our results are in line with the hypothesis that a...

We use the introduction of a fi nancial transaction tax (FTT) in France in 2012 to test competing theories on its impact. We find no support for the idea that an FTT improves market quality by a ffecting the composition of trading volume. Instead, our results are in line with the hypothesis that...