So how does this yen/us$ carry trade really work? I go to a bank, open a yen and a dollar account. Borrow for example 11,861,500 yen at 1,5%, transfer that money into US$ 100,000 for this example. Buy T-bonds at 4.65%. Hedge the Yen exposure and pocket the difference. WhereÂ´s the catch? WhatÂ´s the margin needed? Which banks allow this construction?