In response, banks have turned to foreign exchange swap markets to source US dollars, pushing up the cost significantly (Graph 9). Graph 9  To alleviate the shortage of US dollar funds among European banks, the US Federal Reserve has re-activated its US dollar swap lines with a number of other central banks.
This is to allow these central banks to lend US dollars to banks in their jurisdiction. Until recently, however, banks had not made much use of this facility, instead seeking to reduce their need for US dollars by selling US dollar assets and cutting back on cross-border financing.