This paper shows that high frequency trading may play a dysfunctional role in financial markets. Contrary to arbitrageurs who make financial markets more efficient by taking advantage of and thereby eliminating mispricings, high frequency traders can create a mispricing that they unknowingly...

This paper provides a mathematical analysis of how high frequency traders profi t from their speed with respect to the limit order book. We show that their pro ts can be decomposed into two components. The rest is due to their ability to execute market orders at limit order prices and without...

This paper proposes a method to compute ex-ante trading costs at the intraday level from limit order books. Using nearly 500 of the largest traded companies in the NYSE ArcaBook, we show that these costs have nontrivial intraday dynamics, are negatively related to volume and positively related...

We present a learning algorithm based on simulation and neural networks to solve a stochastic optimal control problem with a large state space using dynamic programming. The problem consists in liquidating a given number of shares of a stock through a limit order book (LOB). The state space...

We study the problem of optimally liquidating a large portfolio position in a limit order book market. We allow for both limit and market orders and the optimal solution is a combination of both types of orders. Market orders deplete the order book, making future trades more expensive, whereas...