The rupee surged 11 paise to 74.77 against the US dollar in opening trade on Tuesday tracking positive domestic equities and weak American currency. At the interbank forex market, the domestic unit opened at 74.78 against the US dollar, gained further ground and touched 74.77 against the US dollar, registering a gain of 11 paise over its previous close. It had settled at 74.88 against the US dollar on Monday. Forex traders said positive trend in the equity markets, weak American currency and sustained foreign fund inflows supported the rupee, while concerns over rising COVID-19 cases weighed on investor sentiment. The dollar index, which gauges the greenback's strength against a basket of six currencies, fell 0.23 per cent to 92.63. -- PTI