The rupee appreciated 25 paise to close at 86.33 (provisional) against the US dollar on Wednesday, supported by positive domestic equities and soft US dollar index. Forex traders said the rupee is likely to witness high volatility with a negative bias ahead of key events in the global and domestic economic landscape. Moreover, the overall uncertainty about the global economy continued to weigh on both currencies and commodities, keeping investors on edge. At the interbank foreign exchange, the rupee opened at 86.56 against the greenback. During the day, the local unit touched an intraday high of 86.30 and a low of 86.71. It finally closed at 86.33 (provisional) against the US dollar, up 25 paise from its previous close. On Tuesday, the rupee fell 13 paise to 86.58 against the US dollar. "We expect the rupee to remain largely weak on underlying strength in the US dollar and overall weakness in the domestic markets. Importer demand for dollars may also pressurise the rupee. However