Nvidia's stock, like a rollercoaster, went down really fast on Tuesday, making it the worst day ever for the company.
The stock lost so much money that it was the biggest one-day loss in the whole United States, like a giant pile of coins disappearing!
Nvidia's boss, Jensen Huang, who owns a lot of the company's stock, lost a lot of money too, about 10 billion dollars!
The stock went down because the government is looking into whether Nvidia is being fair to other companies, kind of like making sure everyone gets to play on the playground.
