The weakening of the US dollar is due to two main factors: firstly, bond repurchase operations have driven down US Treasury yields; secondly, the continued policy interest rate differential between the Federal Reserve and the Bank of Japan has put downward pressure on the USD/JPY exchange rate. The proactive market intervention by the authorities of the two major economies has also led to increasingly similar operating logics for the two asset classes. The U.S. Treasury announced that it would increase the size of its long-term bond repurchase program from $2 billion to $4 billion, effective September 9th. This news caused the dollar to plummet to its lowest level since May. This move pushed down U.S. Treasury yields, a tactic reminiscent of Japan's currency intervention. The market recognizes that the 5.3% yield on 30-year U.S. Treasury bonds is the U.S. Treasury's "pain threshold," just as 164 is a key level for the dollar against the yen in the eyes of Tokyo. The similarities don't stop there; both policymakers have had to confront the pressure of one-sided market movements, using tools to adjust asset prices and hedge against volatility caused by speculative funds. From a fundamental perspective, the decline in the dollar against the yen lacks reasonable support. The significant interest rate differential between the Federal Reserve and the Bank of Japan has led to the yen being heavily sold as a funding currency in carry trades. The Japanese government has had to use funds opportunistically to curb the upward pressure on the dollar against the yen. Now, the U.S. Treasury is also forced to act against fundamentals, actively intervening in the bond market to adjust the yield curve, thereby preventing excessively high long-term interest rates from impacting government debt interest costs and the pace of domestic economic recovery. The rise in US Treasury yields is not solely due to fiscal stimulus and widening fiscal deficits; geopolitical factors and competition from artificial intelligence are also influencing yields. Large-scale technology companies are issuing large amounts of corporate bonds to fund their AI projects. For example, Alphabet's bonds maturing in 2075 have an interest rate of approximately 6.8%. These attractive assets are diverting funds from the US Treasury market, leading to a sell-off and pushing up yields. Institutional funds, seeking to maximize returns, are continuously increasing their allocation to long-term bonds issued by high-quality technology companies, further reducing demand for US Treasuries. In the foreign exchange market, there's a view that the short-selling trend in USD/JPY achieved through coordinated exchange rate intervention by the Bank of Japan will be unsustainable without its cooperation. This means the Bank of Japan must accelerate its monetary tightening, shortening the interest rate hike cycle from once every six months to once every three months; or signal its intention to significantly raise interest rates to levels far above current levels, at least to 2.5%. Only through substantial monetary tightening can the USD/JPY interest rate differential be fundamentally narrowed, weakening the yen's status as a carry trade currency. Conversely, the Federal Reserve presents a clear contradiction. The minutes of the July Federal Open Market Committee (FOMC) meeting showed that a growing number of officials were prepared to vote in favor of tightening monetary policy, with the overall tone of the minutes leaning hawkish. However, for the dollar to weaken, the Fed needs to adopt a cautious approach to interest rate hikes. Meanwhile, Citigroup believes that the main cost the US Treasury pays to control Treasury yields is a weaker dollar. Treasury repurchase operations inject liquidity and suppress long-term yields, which typically weakens the relative returns of dollar assets, thus dragging down the dollar's exchange rate performance.