高频价格变动预测是预测价格在短时间内(比如1 min内)的变化方向(上涨、不变或下跌).用历史的高频交易数据去预测价格变化是一个比较困难的任务,这是因为二者之间的关系是高噪声、非线性和复杂的.为提高高频价格预测准确率,提出了一个端到端的双目标多任务方法.该方法引进了一个辅助目标(高频价格变化率),它和主目标(高频价格变化方向)是高度相关的并且能够提高主目标的预测准确率.此外,每一个任务都有一个基于循环神经网络和卷积神经网络的特征提取模块,它可以学习出历史交易数据和两个目标之间的高噪声、非线性和复杂的时空相依关系.为了缓解多任务方法的潜在的负迁移问题,每个任务的任务间共享部分和任务特有部分被显式地分开.而且,通过一种梯度平衡方法利用两个目标之间的高相关性过滤掉从不一致性中学到的噪声的同时保留从一致性中学到的相依规律,从而提高高频价格变化方向预测准确率.在真实数据集上的实验结果表明:所提方法能够利用高度相关的辅助目标帮助主任务的特征提取模块去学习出更有泛化能力的时空相依规律,最终提高高频价格变化方向预测准确率.此外,辅助目标(高频价格变化率)不仅能够提高特征提取模块的总体效果,而且也提高特征提取模块的不同部分的效果.
High-frequency price movement prediction is to predict the direction(e. g. up, unchanged or down) of the price change in short time ( e. g. one minute ) . It is challenging to use historical high-frequency transaction data to predict price movement because their relation is noisy, nonlinear and complex. We propose an end-to-end multitask method with two targets to improve high-frequency price movement prediction. Specifically, the proposed method introduces an auxiliary target ( high-frequency rate of price change) , which is highly related with the main target( high-frequency price movement) and is useful to improve the high-frequency price movement prediction. Moreover, each task has a feature extractor based on recurrent neural network and convolutional neural network to learn the noisy, nonlinear and complex temporal-spatial relation between the historical transaction data and the two targets. Besides, the shared parts and task-specific parts of each task are separated explicitly to alleviate the potential negative transfer caused by the multitask method. Moreover, a gradient balancing approach is adopted to use the close relation between two targets to filter the temporal-spatial dependency learned from the inconsistent noise and retain the dependency learned from the consistent true information to improve the high-frequency price movement prediction. The experimental results on real-world datasets show that the proposed method manages to utilize the highly related auxiliary target to help the feature extractor of the main task to learn the temporal-spatial dependency with more generalization to improve high-frequency price movement prediction. Moreover, the auxiliary target ( high-frequency rate of the price change) not only improves the generalization of overall temporal-spatial dependency learned by the whole feature extractor but also improve temporal-spatial dependency learned by the different parts of the feature extractor.