Key Points: Nvidia's impressive fourth-quarter performance propels its stock up by 15.12%, driving positive sentiment in the tech sector. Moderna surprises with a fourth-quarter profit, boosting its stock by 10.97%. Rivian faces a significant downturn in its stock price following disappointing production guidance and job cuts. Etsy sees an 8.19% decline in stock value due to lower-than-expected first-quarter sales projections. On Thursday, the U.S. stock market experienced significant gains, driven by robust earnings from Nvidia, a leading artificial intelligence (AI) chip sector player. Investor sentiment was buoyed by Nvidia's stellar fourth-quarter results and optimistic outlook, setting a positive tone ahead...