Identifying Emotional Bias in Investment Decisions

Sarah, a successful portfolio manager, has recently experienced substantial gains in her client's portfolio. However, she is also facing a market downturn that has led to declines in several of her other investments. Sarah's anxiety about the losses is impacting her decision-making process. Despite her previous data-driven strategies, she feels a strong urge to sell her declining positions quickly to avoid further losses, disregarding her long-term investment strategy.

This scenario exemplifies the influence of emotional biases within behavioral finance. Given Sarah's situation, which emotional bias is primarily affecting her investment decisions?