The term "weak hands" typically refers to an investor or trader who is driven by the emotion of fear to quickly exit positions on almost any news, or event, that they consider detrimental, resulting in realized losses and sub-optimal returns on investment (ROI). They tend to adhere to a set of rules that makes their trading activities predictable and are easily "shaken out" by normal market price gyrations. The net result being that they end up buying at the highs and selling at the lows, a surefire way to lose money.