基于灰色系统和神经网络的创业板股票价格预测研究

股票价格预测是投资领域的一个重点关注课题。由于股票价格受到诸多非线性因 素的影响,得到精确的预测结果较为困难。为了消除股票指标的多重共线性,采用Adaptive- Lasso算法对指标变量进行筛选,实现了数据降维。之后,利用灰色预测对股票价格影响指标 进行预测,并在此基础上利用神经网络模型对股票收盘价进行预测。结果表明,利用灰色系统 和BP神经网络结合的模型所得预测结果平均相对误差为0.095,且运行效率较高,对股票预测 具有一定的积极意义。     

Predicting the long-term stock market volatility: A GARCH-MIDAS model with variable selection

We consider a GARCH-MIDAS model with short-term and long-term volatility components, in which the long-term volatility component depends on many macroeconomic and financial variables. We select the variables that exhibit the strongest effects on the long-term stock market volatility via maximizing the penalized log-likelihood function with an Adaptive-Lasso penalty. The GARCH-MIDAS model with variable selection enables us to incorporate many variables in a single model without estimating a large number of parameters. In the empirical analysis, three variables (namely, housing starts, default spread and realized volatility) are selected from a large set of macroeconomic and financial variables. The recursive out-of-sample forecasting evaluation shows that variable selection significantly improves the predictive ability of the GARCH-MIDAS model for the long-term stock market volatility.