The rupee strengthened by 4 paise to 63.35 against the US dollar in early trade today at the Interbank Foreign Exchange on selling of American currency by exporters. A fall in dollar against major world currencies globally also helped strengthen the domestic currency. The rupee had recovered 13 paise to end at 63.39 against dollar yesterday on fag-end selling of dollars by banks and exporters. The benchmark BSE Sensex rose by 154 points to trade at 28,086.