This study examines whether the impact of controlling shareholders' share pledging on firm value varies depending on firms' future earnings growth potential. Using a sample of KOSPI and KOSDAQ-listed firms from 2011 to 2023, the results show that share pledging is generally associated with lower future stock returns, indicating an overall negative market response. This negative effect is more pronounced in firms with low future earnings growth potential, suggesting that investors interpret pledging as a negative signal under high information asymmetry. In contrast, share pledging in high-growth firms is positively associated with future stock returns, and this effect remains statistically significant after controlling for sample heterogeneity using entropy balancing. These findings suggest that the valuation effect of share pledging depends on firm growth characteristics. Overall, the results highlight the importance of considering firms' growth potential and financial context when interpreting share pledging and its implications for firm value.