US stocks dropped sharply Monday — and chipmaker Nvidia lost nearly $600 billion in market value — after a surprise advancement from a Chinese artificial intelligence company, DeepSeek, threatened the aura of invincibility surrounding America’s technology industry.

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.

A frenzy over an artificial intelligence chatbot made by Chinese tech startup DeepSeek was upending stock markets Monday and fueling debates over the economic and geopolitical competition between the U.