The operation —which involved a massive purchase of yen— pushed up the value of the Japanese currency and put pressure on the Japanese stock market. Buy Japanese Yen (JPY) US$5-10 bil.” The red thread linking the U.S. and Japanese economiesFinancial analyst Gastón Lentini explained that for years, to slow the yen’s loss of value, the Japanese government has sold U.S. Treasury bonds. “When it needs to buy yen, it sells those bonds, which drives the price down and pushes the yield up. “As long as U.S. rates stay well above Japanese ones, the fundamental incentives to rebuild those positions will persist,” he added.