Why do smart, capable individuals and teams so often make poor decisions? Running Against the Herd offers new answers to this question by blending insights from behavioral economics with hard-earned lessons from a twenty-five-year investing career. Eddie Perkin draws on his extensive experience leading global investment teams to identify biases that shape our decisions, not just in markets and boardrooms but also in sports, gambling, and everyday life. He shows how groupthink and mental shortcuts—from anchoring and framing to short-termism—impair judgment and shares practical tools to counteract them. Through real-world examples and data from hundred-million-dollar investment decisions, Perkin demonstrates that success depends less on predicting the future than on designing teams and processes that challenge assumptions, welcome dissent, embrace uncertainty, and learn from mistakes. Accessibly written and deeply relevant beyond finance, this book reveals how anyone—investors, leaders, or professionals across fields—can improve their decision-making by understanding its underlying psychology. Running Against the Herd provides a road map for thinking more clearly, working more collaboratively, and achieving better outcomes in a world of uncertainty.