Applying order-level data, this paper examines the relation between the order submission patterns of professional institutional investors and stock price behaviors in the Taiwan Stock Market. We find that the trades of foreign investors (FIs) move the stock prices the most among the professional institutional investors in terms of order imbalance and order aggressiveness. The trading behavior of individual investors tends to conflict with that of FIs and offsets part of the price impacts from FIs' trades. The daily top net-buy (net-sell) stocks of securities investment trust companies (SITCs) have significantly higher (lower) return than those of FIs. Overall, SITCs are found more informed in the short term. Additionally, the price impact of institutional trades is related to information effect and there is a marked asymmetry between the permanent price changes of buys versus sells. The positive contemporaneous daily relation between return and institutional trading is largely driven by net institutional trading positively following past intraday price movements and the contemporaneous price pressures.