Nvidia helped pulled U.S. stock indexes higher Tuesday after they stumbled in the morning on worries about escalations in the Russia-Ukraine war. 

The S&P 500 rose 0.4% after erasing an early drop of 0.7%. The Nasdaq composite also shook off an early loss to turn 1% higher, while the Dow Jones Industrial Average slipped 120 points, or 0.3%.

Nvidia's 4.9% climb accounted for the vast majority of the index’s gain. The chip company’s stock rallied ahead of its profit report for the latest quarter, which is coming on Wednesday, and vaulted its gain for the year to nearly 197% thanks to the craze around artificial-intelligence technology. 

Activity in the options market suggests Nvidia’s profit report may be the most anticipated event on Wall Street for the rest of the year, beating out the upcoming jobs report and even the next meeting of the Federal Reserve on interest rates, according to strategists at Barclays Capital.

It’s “a testament to the outsized impact of AI, and the apparent resurgence of upside chasing by” smaller-pocketed, everyday investors known as retail traders, according to Barclays’ Stefano Pascale and Anshul Gupta.

Nvidia’s rise helped calm the stock market, even as indexes sank across Europe after Russia said Ukraine fired six U.S.-made ATACMS missiles at it. Earlier in the day, Russian President Vladimir Putin informally lowered the threshold for Russia’s use of its nuclear weapons. Both France’s CAC 40 and Germany’s DAX fell 0.7%.

The worries also sent investors into U.S. Treasury bonds, which are seen as some of the world’s safest investments. The rise in their prices in turn lowered their yields, and the 10-year Treasury yield fell to 4.39% from 4.41% late Monday.

Gold also rose 0.6% and recovered some of the losses it sustained following Donald Trump's vivctory in the U.S. presidential election, as investors herded into places traditionally considered safer during times of trouble.