基金似乎知道什么时候是交易的好时机。本文通过建立一个存在时间变化的基金交易模型来正式确定这一想法。本文发现，基金的换手率正向预测了该基金下一期的回报。这个结论来自于笔者对2005年至2022年1620个开放式股票型和偏股混合型基金的研究。结论在统计学和经济学上都是显著的：当期换手率每变化一个单位，就会使基金下一年的业绩增加0.76%。此外，按照基金的投资风格进行分类，本文发现价值风格型基金的换手率对收益率的影响比其他风格类型的基金更大。单经理管理基金的换手率对收益率的影响大于团队管理的基金。

Funds seem to know when it is a good time to trade. This article formalizes this idea by establishing a fund trading model with time variation. We find that the turnover rate of a fund positively predicts its return in the next period. This conclusion comes from the research on 1620 open-end funds and mixed-type funds from 2005 to 2022. The conclusion is significant in both statistics and economics: every unit change in the turnover rate in the current period will increase the fund's performance by 0.76% in the following year. In addition, according to the investment style of funds, we found that the turnover rate of value-style funds has a greater impact on returns than other style funds. The turnover rate of single manager managed funds has a greater impact on returns than that of team managed funds.