Do uninformed traders move prices? Evidence from the Bank of Japan's ETF purchasing program
利用日本央行ETF购买计划作为股票需求的外生冲击，研究发现央行需求越高的股票在购买日异常回报越高，且长期仅部分反转，支持股票需求曲线向下倾斜，即不知情交易者能引起价格永久性变化。
Abstract Using the Bank of Japan (BoJ) ETF purchasing program as an exogenous shock to stock demand, we find that stocks with a higher BoJ demand experience higher positive abnormal returns on BoJ ETF purchase dates, which only partially revert in the long term. Our findings support the hypothesis that stocks have a downward‐sloping demand curve, implying that uninformed traders can cause a permanent shift in price.