ToplineNvidia headed toward a dubious Wall Street record Monday, as the stock at the forefront of the U.S.-led artificial intelligence revolution got a scare from DeepSeek, the Chinese AI company which developed a ChatGPT rival at a fraction of the reported cost of its American peers.

Nvidia, Microsoft, and Alphabet were among the market's top losers on Monday as the rise of DeepSeek rattled investors.

In a matter of days, DeepSeek proved to be so popular as to climb to the top of Apple's App Store, surpassing OpenAI's ChatGPT as the most downloaded app. But for owners of Nvidia stock, and stock traders in general, DeepSeek is on track of becoming a black swan — an unexpected event with extreme consequences.