Apprehensive that the rupee could weaken further as crude oil prices soar, foreign portfolio investors (FPIs) have dumped Indian bonds worth more than $4.5 billion over the past month or so. The sales in the equity market, at close to $1.63 billion over the same time, have been far smaller. However, the foreign exchange outflows have, in turn, aggravated the pressure on the rupee. The rupee lost 38 paise on Wednesday to drop to 68.426 against the dollar, the lowest level in nearly 18 months. Another 40 paise loss would take the currency to the all-time closing low of 68.825 seen on August 28, 2013.