1. Post-opening buying: Let's say a stock rises 5 percent or more during the opening and there's no news about it. Typically, the stock will fall off after 30 minutes of trading. Why? Market makers may be trying to open the stock at an artificially high price to sell off excess inventory they've acquired the day before. However, if the stock doesn't fall after 30 minutes of trading, it's liable to continue rising for the rest of the day. Tactic: Buy at 1/16 above the day's high after the opening. Set a stop at 1/16 below the day's low.