According to CoinMeta, Japan coordinated with the United States to cause the US dollar to depreciate by 3.3% against the Japanese yen, which is the largest fluctuation in two years. US Treasury Secretary Janet Yellen stated that the yen is "very undervalued" and pointed out that "excessive fluctuations are unhealthy." Japan spent a record $73.4 billion buying yen in the last quarter, but the currency still fell to a 40-year low.