The Bank of Japan is set to increase interest rates by 25 basis points to 0.75% on December 19, marking the first hike since January and reaching a 30-year high. This move could exert pressure on Bitcoin, as a stronger yen historically impacts the cryptocurrency's performance. Currently, the yen is trading near 156 against the dollar. The rate hike may also affect altcoins, which could face similar challenges if the yen continues to strengthen. Despite these potential headwinds, carry trades remain stable, supported by yen longs and higher bond yields. Additionally, the Federal Reserve's recent rate cut to a three-year low may help limit yen unwinds.