Mumbai, Dec. 30 -- Indian rupee edged up today amid sustained weakness the US dollar index amid a steady gain in in latest forex reserves data. INR has recovered after testing a one-week low per US dollar amid cautious trades in global fx markets around year-end. The local currency also eyed the Indian government monthly finances data and edged up 18 paise to INR 89.80 per US dollar. On NSE, USD/INR futures eased 0.34% to 90.06. Meanwhile, the key equity barometers ended marginally lower today amid persistent foreign institutional investor (FII) selling and muted trading activity due to the absence of fresh domestic triggers and ahead of the year-end holiday period, while investors stayed cautious ahead of the corporate earnings season. T...