The impact of corporate investments on the market value of quoted manufacturing firms in Nigeria: Evidence from Vector Autoregressive technique Cross-sectional data was obtained from the financial statements of quoted manufacturing firms – Journal of Economics and Sustainable Development. A stock price and earnings per share were utilized as dependent variables where short-term investment policy, long-term investment policy, subsidiary investment and portfolio invest (as independent.) This study utilized panel data methodology and the fixed-effects model as an estimation technique at a 5% level of significance. Both fixed effects, random effects and pooled estimates were tested, and the Hausman test was performed to select an appropriate model. It was discovered that investment policy was responsible for 60.2% of the systematic variation in the stock prices of quoted manufacturing firms. The results showed that short-term portfolio investment, long-term portfolio investment and long-term investments had positive correlations to stock price, but subsidiary investment also negatively correlated with stock prices of manufacturing firms. The risk coefficients for institutional investors denoted that portfolio investment in the short term and portfolio investment in the long term were statistically significant, while statistical insignificance was recorded for long-term investment and subsidiary investment in addition, the findings revealed that investment policy accounted for 69.1% of systematic variations in earnings per share of quoted manufacturing entities. The research indicates that there was a relationship between long-term investment and subsidiary investment with earnings per share where both generated positive Beta while short-term portfolio investment and long-term portfolio Investment were negatively related to the dependent variable (earnings per share) but since their probability coefficients are high it means these independent variables were statically insignificant. The study then confirms the proposition that investment policy governs the quoted manufacturing firms market value in Nigeria. For this reason, it is suggested that senior management allocate enough consideration determining which type and level of investment are desired, as well as maintaining clear signals relating to the investment policies pursued by the firms. 

Keywords: Corporate Investment, Market Valuation, Portfolio Investment, Long Investment Policy, Short Investment Policy.