This paper investigates the relation between selling, general, and administrative (SG&A) expenditure and firm value for companies listed on Korea Stock Exchange. Empirical results show that SG&A expenditures have a positive impact on firm value, suggesting that SG&A expenses are more likely to contribute to value creation through intangible investments, rather than playing a negative role associated with increased agency costs. The analysis of the main components of SG&A expenses reveals that both research and development (R&D) expenses and labor expenses are crucial contributors to firm value. However, when measuring firm value considering the characteristics of intangible capital, I find that building knowledge capital and organization capital in the long term is a key factor in enhancing future firm value. Furthermore, I explore whether the stock market's evaluation of SG&A expenses stems from their value-creation ability or mispricing. I find that, compared to the predictability of operating profit ofSG&A expenses, market participants tend to undervalue current SG&A expenses. This implies that the positive assessment of SG&A expenses in the stock market is more likely influenced by mispricing rather than the value-creation potential of SG&A expenses.