On July 18, the Nasdaq 100 index closed down 2.9% on Wednesday, the largest one-day decline since December 2022. All the "Big Seven" as heavyweights fell, among which NVIDIA (NVDA. O) fell the most, falling more than 6.6%, and Apple (AAPL. O) fell 2.5%. The market value of the "Big Seven" evaporated about 580 billion dollars (about 4.21 trillion yuan) in a single day. Goldman Sachs' trading department said that the S & P 500 index now has only one way to fall, and will not buy on dips.