Indian stock markets tumbled on Thursday, with Sensex closing below 80,000 and Nifty below 24,000 for the first time since late November. The sell-off, driven by hawkish US Fed statements and foreign fund outflows, wiped out Rs 3.8 lakh crore in investor wealth. Selling pressure was broad-based, with ICICI Bank, Reliance, and HDFC Bank leading the decline.