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Collaborating Authors

 Poli, Michael


WATTNet: Learning to Trade FX via Hierarchical Spatio-Temporal Representation of Highly Multivariate Time Series

arXiv.org Machine Learning

Finance is a particularly challenging application area for deep learning models due to low noise-to-signal ratio, non-stationarity, and partial observability. Non-deliverable-forwards (NDF), a derivatives contract used in foreign exchange (FX) trading, presents additional difficulty in the form of long-term planning required for an effective selection of start and end date of the contract. In this work, we focus on tackling the problem of NDF tenor selection by leveraging high-dimensional sequential data consisting of spot rates, technical indicators and expert tenor patterns. To this end, we construct a dataset from the Depository Trust & Clearing Corporation (DTCC) NDF data that includes a comprehensive list of NDF volumes and daily spot rates for 64 FX pairs. We introduce WaveATTentionNet (WATTNet), a novel temporal convolution (TCN) model for spatio-temporal modeling of highly multivariate time series, and validate it across NDF markets with varying degrees of dissimilarity between the training and test periods in terms of volatility and general market regimes. The proposed method achieves a significant positive return on investment (ROI) in all NDF markets under analysis, outperforming recurrent and classical baselines by a wide margin. Finally, we propose two orthogonal interpretability approaches to verify noise stability and detect the driving factors of the learned tenor selection strategy.


Port-Hamiltonian Approach to Neural Network Training

arXiv.org Machine Learning

-- Neural networks are discrete entities: subdivided into discrete layers and parametrized by weights which are iteratively optimized via difference equations. Recent work proposes networks with layer outputs which are no longer quantized but are solutions of an ordinary differential equation (ODE); however, these networks are still optimized via discrete methods (e.g. In this paper, we explore a different direction: namely, we propose a novel framework for learning in which the parameters themselves are solutions of ODEs. By viewing the optimization process as the evolution of a port-Hamiltonian system, we can ensure convergence to a minimum of the objective function. Numerical experiments have been performed to show the validity and effectiveness of the proposed methods. Neural networks are universal function approximators [1]. Given enough capacity, which can arbitrarily be increased by adding more parameters to the model, they can approximate any Borel-measurable function mapping finite-dimensional spaces. Each layer of a neural network performs an affine transformation to its input and generates an output which is then fed into the next layer. Backpropagation [2] is at the core of modern deep learning, and most state-of-the-art architectures for tasks such as image segmentation [3], generative tasks [4], image classification [5] and machine translation [6] rely on the effective combination of universal approximators and line search optimization methods: most notably stochastic gradient descent (SGD), Adam [7] RM-SProp [8] and recently RAdam [9].