Understanding Loss Aversion in Wealth Management Decisions

John is a financial advisor helping Lisa, a 45-year-old client, with her investment portfolio. Recently, Lisa has been feeling anxious about the market's volatility and has expressed a desire to move her investments into cash to avoid potential losses. John considers the behavioral finance concepts that might impact Lisa's decision-making process.

Which of the following concepts most likely explains Lisa's inclination to shift her investments to cash due to her anxiety about market fluctuations?