KATHMANDU: Continuing its downward spiral, the Nepali rupee will tumble to a new all-time low of 115.11 against US dollar on Thursday. As per the exchange rate of Nepal Rastra Bank, the Nepali currency was valued at 114.84 vis-à-vis the greenback on Wednesday. The Nepali currency has come under pressure owing to devaluation of the Indian rupee, against which it is pegged.