This research investigates the influence of Net Profit Margin (NPM), Return on Assets (ROA), and Return on Equity (ROE) on the share prices of companies listed in the LQ45 index of the Indonesia Stock Exchange for the period 2020–2023. Using a quantitative approach, the study employs multiple linear regression analysis based on secondary data collected from 25 Companies that continually appeared in the LQ45 index during the observation period. The findings reveal that NPM has a positive and statistically substantial influence on share price, while ROA and ROE do not exhibit significant effects. These results recommend that investors allocate greater emphasis on bottom-line profitability (NPM) than on operational or equity efficiency when evaluating stock value. The research supports signalling theory, indicating that NPM serves as a strong financial signal in the Indonesian capital market context. However, the relatively low R² value (18.5%) indicates that other variables beyond profitability ratios also influence stock price movements. The research emphasizes the necessity for companies to concentrate on tactics that enhance net profitability and for future research to examine additional financial and non financial determinants of market valuation.