在金融市场典型事实约束下，运用 ARFIMA-FIAPARCH 模型和极值理论分别对条件波动率和标准收益极端尾部建模，计算出各股市的极端风险，进而探讨在不同的市场波动状态下中外股市的极端风险传染效应及其变化规律。通过实证研究发现，沪、深、港三个中国股市之间的极端风险传染效应在剧烈波动期强于相对平静期，熊市期间强于牛市期间。同样地，三个国外股市之间的极端风险传染效应剧烈波动期强于相对平静期，熊市强于牛市。但是，中外股市之间的风险传染效应与上述结论相反，即相对平静期强于剧烈波动期，牛市强于熊市。

在金融市场典型事实约束下，运用 ARFIMA-FIAPARCH 模型和极值理论分别对条件波动率和标准收益极端尾部建模，计算出各股市的极端风险，进而探讨在不同的市场波动状态下中外股市的极端风险传染效应及其变化规律。通过实证研究发现，沪、深、港三个中国股市之间的极端风险传染效应在剧烈波动期强于相对平静期，熊市期间强于牛市期间。同样地，三个国外股市之间的极端风险传染效应剧烈波动期强于相对平静期，熊市强于牛市。但是，中外股市之间的风险传染效应与上述结论相反，即相对平静期强于剧烈波动期，牛市强于熊市。

针对 R/S 系列分析方法在估计 H 参数时存在一定偏差，从而导致分析结论产生分歧的问题，提出用非线性估计方法提高 R/S 系列分析估计 H 参数的精确度，同时结合 ARFIMA 模型对估计精度进行了验证.最后应用非线性 R/S 方法揭示中国股市主要指数和个股收益序列中的长期记忆效应.

In this paper, we have examined the long memory property of Indian stock market by analyzing the trading volume series. Given the absence of trading volume index data, we have constructed trading volume series for the Indian stock market. We used maximum likelihood method to analyze the constructed trading volume index. The estimation of ARFIMA model, obtained a signicant parameter for the order of fractional integration, and this could be consistent with the long autocorrelations observed in the trading volume series. The ndings that stock trading volume is a long memory process is robust, given dierent estimating methods, different subsamples, temporal aggregation and tests on individual stocks. Because of the conditional heteroscedasticity in the series, we have also carried out ARFIMAGARCH procedures to check whether long persistence were robust in the presence of conditional heteroscedasticity.