The rupee fell by 42 paise to close at 81.82 against the US dollar Monday, snapping its two-session gaining streak as heavy selling in domestic equities and a spike in crude oil prices weighed on the local unit. Besides, a stronger greenback against key rivals and weak macro data put pressure on the domestic currency, forex dealers said. At the interbank foreign exchange market, rupee opened weak at 81.65, fell to 81.98 before ending at 81.82, down 42 paise over its previous close.