Mumbai, Aug 4 (PTI) The rupee witnessed a range-bound trading against the US dollar in early trade on Friday, as the support from positive domestic equities was negated by firm crude oil prices. Forex traders said the rupee opened on a flat note as losses in dollar index, and positive Asian currencies supported sentiments, while rise in crude oil prices dented investors. At the interbank foreign exchange, the rupee was trading in a narrow range. It opened at 82.73 against the dollar, and touched a low of 82.77 and a high of 82.72.