We’ve all felt it. Your heart pounds as the chart spikes or plummets. A surge of fear or FOMO (Fear of Missing Out) floods in, and suddenly your carefully crafted plan evaporates. In those moments, a primal part of your brain seizes control. Neuroscientists call it an amygdala hijack, an emotional takeover where instinct trumps intellect. For even the most seasoned traders, this hijack can trigger split-second decisions that defy all logic and discipline.

Hijacked by Emotion

The term “amygdala hijack” describes when the brain’s fear center (the amygdala) overrules the rational brain. It’s essentially a fight-or-flight reflex gone awry. Originally meant to protect us from saber-toothed tigers, this response now misfires at modern threats like a sudden market selloff or a missed opportunity. Under stress, the amygdala reacts instantaneously, flooding us with alarm and urgent impulses. The rational prefrontal cortex, which normally weighs options and enforces discipline, goes temporarily offline. In the trading world, that split-second neural takeover can be costly. An emotional hijack might cause you to click buy or sell in a panic, only to wonder later: “What was I thinking?” In truth, you weren’t. Your reflexes were.

Brain Under Stress: Amygdala vs. Prefrontal Cortex

Modern neuroscience reveals a physiological battle unfolding in a hijacked brain. Stress hormones like adrenaline and cortisol gush into the bloodstream, priming your body for action. Your pulse races, breaths shorten, vision narrows. In the brain, these chemicals hit the prefrontal cortex – the area for reason, focus, and self-control) – like a breaker switch. Studies show that acute stress rapidly weakens the prefrontal cortex’s top-down control while strengthening the reactive circuitry of the amygdala. In essence, your smart brain dims as your survival brain.