Bangladesh Bank yesterday issued show-cause notices to 11 banks for trading US dollars at prices higher than the inter-bank declared rates.

The banks have been asked to reply to the notices within three days. The US dollar appreciated heavily against the taka over the last seven-eight days despite injection of $102 million into the market by the BB during the period.

The inter-bank exchange rate of the dollar shot up to Tk 81.90 on Monday from Tk 81.20 seven days back and from Tk 78.63 a year ago, according to data from the central bank.