This study investigates short-term returns of stocks net bought or net sold by institutional investors, and examines whether institutional investors’ net buy-and-sell has implied information for stock prices. This study focuses on stocks which are top ten weekly net-bought or net-sold by institutional investors in terms of the number of shares transaction or the amount of dollar transaction during the period from 2001 to 2013. Empirical results show that stocks net bought (net sold) by institutional investors experience a positive (negative) weekly return during the week institutional investors net buy (net sell) those stocks. Except for stocks net sold by security dealers, significant positive (negative) returns for those stocks can be found in the following four weeks. However, the magnitudes of post returns for net-sold stocks are lower than those for net-bought stocks. Such finding implies that institutional investors’ net buy-and-sell, especially for the net buying, do have implied information for stock valuations, and individual investors can earn a certain return following institutional investors’ net buy-and-sell. Our results are robust after adjusting for the market, size, and book-to-market ratio risk factors.