Bitcoin's correlation with the Japanese yen has reached a record high, with a 90-day correlation coefficient of 0.86, according to TradingView data. This indicates that 73% of Bitcoin's price movements over the past 90 days have mirrored those of the yen, as measured by Pepperstone's JPY Index. The JPY Index tracks the yen's strength against major currencies like the euro, U.S. dollar, Australian dollar, and New Zealand dollar. This strong correlation suggests that Bitcoin's price is now significantly influenced by yen fluctuations, reducing its role as a portfolio diversifier. The yen has been in a downtrend since April, driven by concerns over Japan's fiscal debt sustainability, which has affected both Bitcoin and the yen's performance. Despite this, correlations between cryptocurrencies and traditional assets can be transient, and market dynamics may shift again.