Here are 10 things to know about the markets today:
The Sensex ended 1,114.82 points (2.96 per cent) lower at 36,553.60 and the Nifty settled at 10,805.55, down 326.30 points (2.93 per cent) from its previous close - their lowest levels since July 16.
Federal Reserve Vice Chair Richard Clarida said on Wednesday that the US economy remains in a "deep hole" of joblessness and weak demand, and called for more fiscal stimulus, noting that policymakers "are not even going to begin thinking" about raising interest rates until inflation hits 2 per cent.
IndusInd Bank, Tata Motors, Bajaj Finance, Grasim and Tata Consultancy Services, closing between 5.45 per cent and 7.45 per cent lower, were the worst hit among the 47 laggards in the 50-scrip Nifty index.
Infosys, Reliance Industries, TCS and ICICI Bank were the biggest drags on Sensex. The four accounted for a loss of more than 500 points in the index.
Analysts say concerns about a delayed recovery from the damage caused by the coronavirus pandemic, amid fears about a second wave of infections, shook investors.
"The correction in the market, led by the mother market United States, is a normal, healthy and desirable correction, which will make markets look more realistic and rational," VK Vijayakumar, chief investment strategist at Geojit Financial Services, told NDTV.
"The markets recovered after the crash in end-March and ran up too much too fast exposing the economy-market disconnect. The rally was triggered and sustained by the huge liquidity and the historically low interest rates. It is difficult for rallies to sustain without earnings support. For he Nifty, 10,800 is the next support," Mr Vijayakumar added.
Volatility intensified as investors rushed to settle their F&O positions as monthly derivatives (futures and options) contracts expired today, said analysts. The NSE's India VIX Index - which gauges the expectation of volatility in the near term - climbed up 12.32 per cent, in its biggest one-day jump since August 31.
The Sensex shed 2,559.87 points, marking a decline of 6.54 per cent, in the September series, and the Nifty lost 753.7 points (6.52 per cent) - after rising in each of past three months.
Heavyweight TCS shares fell 5.50 per cent to Rs 2,331.50 apiece on the BSE, extending losses to a second straight day, after Shapoorji Pallonji group - the largest minority shareholder in Tata Group - said on Tuesday it wanted to separate interests from the autos-to-steel conglomerate.
(With inputs from agencies)