The rupee firmed up by 10 paise to 70.06 against the US dollar in early trade at the Interbank Forex market today on selling of the American currency by exporters and banks amid fresh foreign funds inflow. Besides, the dollar's weakness against other currencies overseas gave the rupee strength, dealers said. They said a record opening of the domestic equity markets, too kept the rupee firm. Yesterday, the rupee had retreated sharply to hit a record closing low of 70.16 against the dollar, plunging by 25 paise despite a huge rally in equities and easing worries over near-term monetary policy tightening by the US Fed. Meanwhile, the BSE Sensex climbed 181.75 points, or 0.46 per cent, to quote a fresh life-time high of 38,875.86 in opening trade. The NSE Nifty too scale a new peak of 11,751.20 by surging 59.25 points. Foreign institutional investors (FIIs) bought shares worth a net of Rs 252.52 crore, while domestic institution investors (DIIs) accumulated shares to the tune of Rs 1,117.24 crore yesterday, as per provisional data.