In India, GST introduced in July 2017 was a major event for the Economy. It subsequently impacted all the business sectors and companies operating within the economy. In such cases, it is important to gauge the impact of this new taxation system to analyze the outcome. This research explores the effect of GST on the net profits and stock prices of Maruti Suzuki, Tata Motors, Mahindra & Mahindra, Honda, Ashok Leyland, Bajaj Auto, TVS Motors, Toyota, Hero Motor Corp, and Ford Motors. For this purpose, pre-GST and post-GST analysis was conducted through a paired t-test using SPSS for 2 variables i.e., net profits and stock prices. I have gathered data from the NSE and financial reports of the companies for a comparable period of 7 years before and 7 years after the GST implementation It was found that there is no significant effect on the net profits of the selected companies. The trends in stock prices of companies, except TVS Motors seemed to be unaffected due to the introduction of GST.