The yen hit its highest level in 14 years on the dollar on Friday and jumped against higher-yielding currencies as investors cut risk trades on concerns about debt problems in Dubai, while Japan signalled growing discomfort with the surge. After plummeting on Thursday, the dollar plunged to a new 14-year trough below 85 yen as investors unwound yen-funded carry trades in the likes of the Australian and New Zealand dollars. In a market made thinner by a U.S. holiday on Thursday, Japanese exporters fuelled the drop by buying yen ahead of the month-end, while traders also dumped dollars due to option triggers at 85.00 yen, and sell orders kicked in below that level.