The rupee plunged by 52 paise to close at 74.87 (provisional) against the US dollar on Monday amid a lacklustre trend in the domestic equities as investors fretted over the prospects of lockdown in some parts of the country amid a surge in Covid-19 cases.
At the interbank forex market, the local unit opened at 74.80 against the greenback and traded in the range of 74.79 to 75.05 during the day.
The rupee finally ended at 74.87 against the American currency, registering a fall of 52 paise over its previous close. On Friday, the rupee had settled at 74.35 a dollar.
The dollar index, which gauges the greenback's strength against a basket of six currencies, fell 0.49 per cent to 91.11.
Forex traders said the surge in coronavirus infections over the weekend increased the risk of more broad-based lockdowns.
Delhi Chief Minister Arvind Kejriwal announced a lockdown from 10 pm on Monday night till 5 am next Monday in view of an exponential rise in coronavirus cases and the city's health system being stretched to its limits.
India's total tally of Covid-19 cases crossed 1.50 crore with a record single-day rise of 2,73,810 new coronavirus infections, while the active cases surpassed the 19-lakh mark, according to the Union Health Ministry data updated on Monday.
Registering a steady increase for the 40th day in a row, the active cases have increased to 19,29,329 comprising 12.81 per cent of the total infections, while the national Covid-19 recovery rate has dropped to 86 per cent.
Meanwhile, Brent crude futures, the global oil benchmark, was trading 0.33 per cent down at USD 66.55 per barrel.
On the domestic equity market front, the BSE Sensex ended 882.61 points or 1.81 per cent lower at 47,949.42, while the broader NSE Nifty declined by 258.40 points or 1.77 per cent to 14,359.45.
Foreign institutional investors (FIIs) remained net buyers in the capital markets, as they purchased shares worth Rs 437.51 crore on Friday, as per provisional data.