This paper examines transactions data regarding the market's reaction to 258 takeover announcements on the Toronto Stock Exchange (TSE) from 1977 to 1989. The study analyzes volatility and volume of target firm's stock during the first trading day following a takeover announcement. A cross-sectional analysis relates this intraday volatility and volume to various aspects of a takeover announcement that proxy for the certainty of payoff to shareholders. Post-announcement volatility is highest when takeover announcements involve share exchange bids which are contested. Trading volume is highest when bids are contested and involve a large initial price change.