智通财经网·2025-05-21 00:21Core Viewpoint - Moody's downgraded the U.S. debt rating due to the increasing deficit, rising debt interest, and declining debt affordability, which has led to significant market volatility in U.S. stocks and bonds [1][2][6] Group 1: Reasons for Downgrade - The downgrade was primarily driven by the expansion of the U.S. deficit and anticipated increases in debt interest payments, with Moody's projecting the federal deficit to reach nearly 9% of GDP by 2035, up from 6.4% in 2024 [2] - The backdrop of the downgrade includes rising U.S. Treasury yields since 2021, which have contributed to a decrease in debt affordability [2] - The potential passage of Trump's tax cut plan, which could exacerbate the deficit, is also a significant factor in the downgrade [2][3] Group 2: Market Reactions - Following the downgrade, there was a brief but significant fluctuation in U.S. stocks and bonds on May 19, which was later stabilized by remarks from U.S. government and Federal Reserve officials [1][6] - Historical data indicates that sovereign rating downgrades have a more pronounced short-term negative impact on U.S. stocks, lasting about 1-2 weeks, while the long-term U.S. Treasury yields experience only temporary effects [5] Group 3: Legislative Developments - On May 19, Trump's tax cut plan passed the House Budget Committee vote, with expectations of further legislative progress, which could intensify fiscal pressures [3][6] - The tax cut plan includes measures that would permanently reduce personal income taxes and extend estate tax exemptions, contributing to an estimated $3.8 trillion increase in the deficit by 2034 [3]