Core Viewpoint - The article discusses the relationship between interest rates and the bull-bear cycles of dollar bonds, emphasizing that rising interest rates typically lead to a bear market for bonds [3][6]. Group 1: Interest Rates and Bond Market - Interest rates are a significant factor influencing both dollar and renminbi bonds, with rising rates generally indicating a bear market for bonds [3][6]. - The formula for interest rates is given as interest = interest/price, indicating that if interest rates increase, bond market values tend to decrease [4][5]. - Conversely, if interest rates decrease, bond market values are likely to increase [6]. Group 2: Recent Trends in Bond Yields - The article highlights the recent trend in U.S. 10-year Treasury yields, which fell from around 3% in 2019 to approximately 0.5% in early 2020, contributing to a bull market for U.S. bonds during that period [8]. - Starting in 2021, the yields on U.S. 10-year Treasury bonds significantly increased, reaching around 4% to 5%, which corresponds to a bear market for bonds [8][9]. - The fluctuations in interest rates have led to corresponding volatility in short-term, medium-term, and long-term bond funds in the U.S. market over the past few years [9].