Sou Hu Cai Jing·2025-05-20 01:18Group 1 - Moody's downgraded the US credit rating from AAA to Aa1, marking the last major rating agency to do so, which led to an immediate 1% drop in the S&P 500 index [3] - Retail investors responded by buying $4.1 billion in stocks in a single day, setting a record for the highest amount purchased in that time frame, which helped the S&P 500 recover from an early drop of nearly 1.1% [3] - Retail trading volume surged to 36%, surpassing the previous peak in April, with significant purchases in stocks like Tesla and Palantir, while Nvidia faced selling pressure [3] Group 2 - Wall Street professionals remained calm, with firms like Morgan Stanley suggesting to "buy the dip" and HSBC viewing any decline as an opportunity to accumulate [3] - Retail investors have shown strong performance, with net purchases exceeding $50 billion in recent weeks, outperforming many professional institutions [3] - The downgrade by Moody's is seen as a signal rather than an endpoint, with long-term concerns about the US's $36 trillion debt and rising interest payments, which are projected to reach 30% of fiscal revenue by 2035 [4]