Hedge funds have become highly bullish on the Japanese yen, marking their largest 'long' positions in eight years, according to McGeever. This shift comes as futures traders, noted by Kit Juckes, transition from significant short positions to the biggest long bet since 2016. The yen has strengthened past 140 yen per US dollar for the first time in a year, prompting forex margin traders in Japan to unwind their long positions. The upcoming meetings of the Federal Reserve and the Bank of Japan are also influencing market sentiment.