股票回购作为一种股利分配政策和资本运作方式,利用自有资金或者是融资收购本企业发行在外的股份,将其库藏或注销,在外资本市场是常用的。以估计期为基础运用GARCH模型预测正常其正常收益率再与实际收益率相互比较计算累计异常报酬率,发现问题并提出可行的改善方法。 Stock repurchase, as a kind of dividend distribution policy and capital operation mode, uses its own funds or financing to acquire the shares which are issued by the enterprise and stores or cancels it in the foreign capital market. Based on the estimation period, the GARCH model is used to predict the normal return rate and the actual return rate to compare with each other to calculate the cumulative abnormal return rate, find out the problem and propose feasible improvement methods.