Equity benchmark index Sensex nosedived on Monday after two consecutive days of gains, as investors rushed to take profits amid the unabated selling of stocks by foreign investors.
Analysts said investors turned defensive ahead of this week's US Federal Reserve policy decision, which further weakened the sentiment.
The 30-share BSE Sensex plunged by 609.68 points, or 0.71 per cent, to close at 85,102.69.
During the day, it plummeted by 836.78 points, or 0.97 per cent, to hit the intraday low of 84,875.59.