India's top IT firms, including TCS and Infosys, have seen their market value plummet by at least 50% from peak levels, erasing nearly Rs 19.28 lakh crore. This brutal correction is fueled by macroeconomic stress in North America and the disruptive potential of generative AI. Analysts warn of further de-rating as the sector grapples with these structural changes and cautious global economic outlooks.