NvidiaNVDA stock has pulled back from recent highs amid concerns of a bubble in artificial intelligence stocks.Last week, OpenAI Chief Executive Sam Altman told reporters that he thinks the AI market is in a bubble,

Nvidia (NASDAQ: NVDA) shares fell 3.5% on Tuesday, closing at $175.64, as tech stocks broadly pulled back following a recent rally. The chipmaker traded 183 million shares, just above its three-month average of 181 million, signaling a cooling of momentum after reaching record highs earlier this month.

Following the robust rally, NVDA's valuation has reached an elevated level, with its Price-to-Sales (P/S) at 30, markedly higher than the sector median of 3. This suggests the stock is priced at a premium compared to its peers.

U.S. stock indexes ended mixed after Nvidia, Palantir and other superstar stocks pared most of their steep losses from the morning.

This AI infrastructure play has delivered bigger gains than its larger peers since going public earlier this year.

The week’s biggest news for Wall Street is likely arriving on Friday, when Federal Reserve Chair Jerome Powell will give a highly anticipated speech in Jackson Hole, Wyoming. The setting has been home to big policy announcements from the Fed in the past, and the hope on Wall Street is that Powell will hint that an interest rate cut is coming soon.

Just four Big Tech stocks — Nvidia, Microsoft, Meta, and Broadcom — account for 60 percent of the benchmark index’s total returns so far this year, according to a new analysis from DataTrek Research. They’re also responsible for pushing headline valuation levels to dot-com bubble levels.

A Pivotal Moment for Nvidia As the summer earnings season winds down, Big Tech giants like Microsoft (NASDAQ:MSFT), Meta Platforms (NASDAQ:META), Amazon (NASDAQ:AMZN), and Alphabet (NASDAQ:GOOG)(NASDAQ:GOOGL) have delivered robust quarterly results,