DeepSeek’s ChatGPT competitor quickly soared to the top of the App Store, and the company is disrupting financial markets, with shares of Nvidia dipping 17 percent to cut nearly $600 billion from its market cap on January 27th, which CNBC said is the biggest single-day drop in US history.

Entrepreneur Marc Andreessen, known for co-writing Mosaic, one of the world’s first web browsers, wrote Sunday on X that “DeepSeek R1 is AI’s Sputnik moment,” likening it to the space race between the U.S. and the Soviet Union and the event that forced the U.S. to realize that its technological abilities were not unassailable.

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.