We measure net arbitrage trading by the difference between abnormal hedge fund equity holdings and abnormal short interest on a stock. In the cross section, net arbitrage trading strongly predicts future stock returns. This predictability is not due to temporary price pressure, cannot be produced using total institutional holdings, but is consistent with information advantage and copycat tradin...

In this paper a portfolio optimization algorithm based on Evolution Strategies is presented. This method makes use of artificial trading experts discovered earlier by a genetic algorithm. These experts, consisting of technical analysis rules, are trained to process financial time series and to generate trading advice. Evolution Strategies lead to the optimization of portfolio structures where i...

We propose to train trading systems and portfolios by optimizing objective functions that directly measure trading and investment performance. Rather than basing a trading system on forecasts or training via a supervised learning algorithm using labelled trading data, we train our systems using recurrent reinforcement learning (RRL) algorithms. The performance functions that we consider for rei...

The efficient functioning of financial markets is important for growth across the world, affecting businesses, society and individuals. Stock trading, a key activity within financial markets, is undergoing major transformation fuelled by advances in information systems techniques. Our motivation is in the development of stock trading systems that are robust and are transparent to regulators, tr...

We investigate non-linearities in the stock return trading volume relationship by using daily data for 16 European countries in an asymmetric vector autoregressive model. In this framework, we test for asymmetries and analyze the dynamic relationship using a simulation based procedure for computing asymmetric impulse response functions. We find that stock returns have a significant influence on...

In the digital economy of information and communication technology, several organizations from various industries are jumping onto the bandwagon of offering consumer-oriented electronic commerce applications. In Singapore, Internet Stock Trading has been at the forefront of this trend since 1998. However, to-date, the penetration rate of online trading remains low. As such, this paper attempts ...

This study examines the pattern of active versus passive trading in UK equities over the period 1991-2005. We describe a metric to analyse trading activity and volumes in the UK FTSE350 and AIM markets, with emphasis on industrial and size-based effects. Our findings indicate that active stock picking has been consistently declining in the UK market over the period studied for all markets, size...

Asset pricing formulas generated from representative agent models help in computing the fundamental values of assets that investors plan to hold forever. In contrast, in an economy with heterogeneous agents and active trading, stock prices will persistently deviate from the expected fundamental value even without introducing any explosive bubbles. Particularly, the introduction of heterogeneous...

Geometric phases describe how in a continuous-time dynamical system the displacement of a variable (called phase variable) can be related to other variables (shape variables) undergoing a cyclic motion, according to an area rule. The aim of this paper is to show that geometric phases can exist also for discrete-time systems, and even when the cycles in shape space have zero area. A context in w...