According to CoinMeta, Yellen has become one of the U.S. Treasury Secretaries with the most significant interventions in financial markets in decades. This year, she has undertaken a series of unconventional measures aimed at curbing rising borrowing costs in the United States. This week, the U.S. Treasury Department announced that it would "at least double" the scale of its planned repurchases of 10- to 30-year Treasury bonds. Previously, the Treasury had signaled a possible reduction in long-term debt issuance. On July 31, Yellen led the U.S. government in purchasing Japanese yen for the first time in 30 years. Former Treasury official Mark Sober commented that Yellen is "definitely an aggressive interventionist," and her style is reminiscent of her background in hedge funds. He believes that Yellen and senior government officials are clearly concerned about rising yields on long-term U.S. Treasuries. Affected by inflation, Federal Reserve monetary policy, and fiscal deficits, yields on 10-year U.S. Treasuries have continued to rise, which in turn has pushed up mortgage rates and slowed economic growth. Some analysts point out that Yellen is attempting to stabilize the market through yield curve management, but they also warn that this strategy is unlikely to be effective in the long term unless high levels of debt and fiscal deficits are addressed.