US stocks faced a major decline on Monday, particularly impacting Nvidia, which lost nearly $600 billion in market value following the introduction of a new AI model, R1, by Chinese startup DeepSeek. This model, which operates at a lower cost than offerings from US tech giants, raised fears about America’s tech dominance. The Nasdaq index dropped 3.1%, while the S&P 500 fell 1.5%. Nvidia’s shares plummeted nearly 17%, marking the largest single-day market value loss in history. Other tech companies, including Meta and Alphabet, also suffered declines. This shakeup led to investment shifts away from tech towards other sectors, as investors reassess the competitive landscape.