The US stock market opened with a mixed performance, with the Dow Jones Industrial Average nearly flat, while the S&P 500 and the Nasdaq indices rose by 0.39% and 0.79% respectively. The tech sector led the charge, with Nvidia (NVDA.O) seeing an increase of 3.5% at the opening.

Nvidia's Blackwell chips have gone into production, and the company plans to upgrade its artificial intelligence accelerator annually. This news has boosted investor confidence in the company, leading to a significant increase in its stock price.

Meanwhile, GameStop (GME.N) experienced a surge of over 72% at the opening, making it one of the top performers in the market. This significant increase is attributed to a retail investor, often referred to as the 'big brother' among US retail investors, who shared a screenshot of his $116 million position in GameStop.

The retail investor's massive position in GameStop has sent shockwaves through the market, with many investors taking notice of the significant increase in the company's stock price. This has led to a surge in trading activity, with many investors looking to get in on the action.

In conclusion, the US stock market opened with a mixed performance, with Nvidia and GameStop leading the charge. The tech sector continues to be a key driver of the market, with Nvidia's Blackwell chips and GameStop's surge in stock price making headlines. As the market continues to evolve, it will be interesting to see how these trends play out and what impact they will have on the broader market.