本文采用跳-扩散随机波动率模型研究沪深300股指期货上市对现货市场波动的影响。通过MCMC方法估计模型参数,对股指期货上市前后指数连续波动和跳跃特征进行比较分析,并与股指期货各指标作比较。研究发现,股指期货的上市确实起到了稳定现货市场的作用,上市短期内现货市场波动增大,随着时间增加现货市场波动逐渐降低,但是这一稳定效果主要体现在指数波动率的连续部分。股指期货上市后,指数连续波动向均值回归速度加快,并呈现出逐渐降低的趋势;“杠杆效应”在经历短暂的消失后逐渐显现;指数跳跃波动在总波动中所占比重较高,但随着交易时间增加,指数平均跳跃次数和跳跃波动所占比重逐渐降低。
The impact of CSI 300 index futures on the volatility of cash market is examined in this paper by using jump diffusion stochastic volatility models. The parameters are estimated in terms of MCMC method, the volatility and jump features of cash market before index futures is listed are compared with those of cash market after index futures, and are also compared with that of futures market. It is found that index futures do have stabilizing effect for cash market, but it mainly happens in continuous part of index volatil- ity. Continuous volatility of index accelerates its mean reversion speed with the decreasing trend, and the leverage effect of index begins to appear with the time evolving although there is no leverage effect at the beginning. The proportion for jump volatility of index is high, but jump size and jump proportion appears to be decreasing.