Yen slumps to two-week low after BOJ rate hike underwhelms ↧ ↧ Yen slumps to two-week low after BOJ rate hike underwhelms The yen sank to a two-week ​low against the dollar on Friday after two policy makers at the Bank of Japan dissented from a ‌widely expected decision to raise interest rates, raising doubt among traders about the likelihood of further hikes.