Key Takeaways AI stocks had a volatile week as Wall Street reckoned with the implications of a sophisticated, cost-efficient AI model from Chinese start-up DeepSeek.Semiconductor stocks such as Nvidia and Broadcom sold off on Monday as investors worried DeepSeek's efficiencies would temper enthusiasm for AI infrastructure spending.

DeepSeek, a Chinese artificial intelligence (AI) start-up, is sending shock waves through the U.S. tech sector by demonstrating its latest AI assistant, which achieves performance comparable to or even surpassing some of the world's best chatbots.

Some AI researchers hailed DeepSeek’s R1 as a breakthrough on the same level as DeepMind’s AlphaZero, a 2017 model that became superhuman at the board games Chess and Go by purely playing against itself and improving, rather than observing any human games.

Here’s what you need to know about DeepSeek, the Chinese AI startup that rattled markets as its app dethroned OpenAI's as the most-downloaded free app in the U.S. on Apple.

DeepSeek stunned the tech world with the release of its R1 "reasoning" model, matching or exceeding OpenAI's reasoning model for a fraction of the cost.

The startup DeepSeek was founded in 2023 in Hangzhou, China and released its first AI large language model later that year. Its CEO Liang Wenfeng previously co-founded one of China’s top hedge funds, High-Flyer, which focuses on AI-driven quantitative trading.

Stocks rose Friday as Apple led a broad rally following a strong investor reaction to its quarterly earnings report and the market closes out a whirlwind week highlighted by Nvidia’s record-breaking losses in reaction to China’s DeepSeek cheaper AI model and a flurry of earnings reports.