On February 25th, Steve Cohen, the hedge fund billionaire and founder of Point72, said in a speech in Miami that the US stock market may be affected by the Trump administration's policies. Cohen expects US economic growth to slow from 2.5% to 1.5% in the second half of 2025, which is "the first time in a while that he feels very negative". Cohen pointed out that the Trump administration's tariff policy is essentially a tax, which may trigger international trade retaliation; at the same time, immigration restrictions will affect labor force growth, and the anti-corruption initiative of the Department of Government Efficiency (DOGE) is essentially austerity policies. The combination of these factors will have a negative impact on the economy. In the context of the S & P 500 index rising by more than 50% since the beginning of 2023 and NVIDIA rising by 800%, the current market valuation is at an all-time high, and most investors such as hedge funds and retail investors are approaching the limit of their holdings. The market downside risk is significant. It is reported that Point72 has been called "the craziest money-making machine on Wall Street". Cohen has also been selected by the US media as the most influential trader in Wall Street's history. He is also the prototype of the financial tycoon Bobby Axelrod in the famous American TV series "Billions/Financial War". According to the analysis of the trading department of Goldman Sachs, if the stock falls by 10% in a month, it can trigger a systemic sell-off of about 200 billion US dollars, of which one-third comes from the US market.