Data Scaling Effect of Deep Learning in Financial Time Series Forecasting

For years, researchers investigated the applications of deep learning in forecasting financial time series. However, they continued to rely on the conventional econometric approach for model training that optimizes the deep learning models on individual assets. This study highlights the importance of global training, where the deep learning model is optimized across a wide spectrum of stocks. Focusing on stock volatility forecasting as an exemplar, we show that global training is not only beneficial but also necessary for deep learning-based financial time series forecasting. We further demonstrate that, given a sufficient amount of training data, a globally trained deep learning model is capable of delivering accurate zero-shot forecasts for any stocks.