The SPDR Portfolio S&P 500 ETF (SPLG) closed at $70.52 on January 27, down 1.38%, as the S&P 500 index fell 1.46% to 6,012.28 amid a tech sector sell-off triggered by the release of DeepSeek's AI model. The introduction of DeepSeek, an open-source AI solution, has raised concerns about its potential to disrupt profits for major U.S. tech companies, leading to a sharp decline in tech stocks. Nvidia and Broadcom, significant components of the S&P 500, saw substantial drops of 14.88% and 15.16%, respectively, as investors reassessed the competitive landscape in AI. The broader market was also affected by fears of overvaluation, with the S&P 500's price-to-earnings ratio peaking recently. The sell-off was exacerbated by high trading volumes, with SPLG's volume reaching 131.33% of its average.