We study the effects of fee structures on fund managers’ strategies for locking in profits. Utilizing the optimal stopping time method, we identify two critical portfolio value thresholds that signal when a manager will choose to lock in profits. Fee components such as management fees, self-investment ratios, and high-water marks significantly influence these decisions. Specifically, higher management fees are associated with increased risk aversion, leading to a narrower continuation region, indicating a preference for lower risk. Conversely, performance fees encourage greater risk-taking. We use the S&P 500 Index and NASDAQ Composite index as representatives of managers’ portfolios and apply our model to illustrate how managers adjust their profit-locking strategies in response to their desired rewards.