Elon Musk on Monday threatened Apple with legal action over alleged antitrust violations related to rankings of the Grok AI chatbot app, which is owned by his artificial intelligence startup xAI. 

“Apple is behaving in a manner that makes it impossible for any AI company besides OpenAI to reach #1 in the App Store, which is an unequivocal antitrust violation. xAI will take immediate legal action,” Musk wrote in a post on social media platform X.

Apple did not immediately respond to CNBC’s request for comment.

“Why do you refuse to put either X or Grok in your “Must Have” section when X is the #1 news app in the world and Grok is #5 among all apps? Are you playing politics?” Musk said in another post.

Apple last year tied up with OpenAI to integrate ChatGPT into its iPhone, iPad, Mac laptop and desktop products. Musk at that time had said that “If Apple integrates OpenAI at the OS level, then Apple devices will be banned at my companies. That is an unacceptable security violation.”

CNBC confirmed that ChatGPT was ranked No. 1 in the top free apps section of the American iOS store, and was the only AI chatbot in Apple’s “Must-Have Apps” section.

Prior to his legal threats against Apple, Musk had celebrated Grok surpassing Google as the fifth top free app on the App Store.

OpenAI on Thursday announced GPT-5, its latest and most advanced large-scale AI model, following xAI Grok 4 chatbot released last month.

This is not the first time Apple has been challenged on antitrust grounds. The Department of Justice last year sued Apple over iPhone ecosystem monopoly.

In June, a panel of judges denied Apple’s emergency application to halt the changes to its App Store. The iPhone maker had requested the appeals court to pause an order that said the company could no longer charge a commission on payment links inside its apps nor tell developers how the links should look.

— CNBC’s Kif Leswing contributed to this story.

President Donald Trump said Monday that he and members of his cabinet met with Intel CEO Lip-Bu Tan, days after he called on the head of the chipmaker to resign. Intel shares rose 2% in extended trading.

“I met with Mr. Lip-Bu Tan, of Intel, along with Secretary of Commerce, Howard Lutnick, and Secretary of the Treasury, Scott Bessent,” Trump wrote in a post on Truth Social. “The meeting was a very interesting one. His success and rise is an amazing story. Mr. Tan and my Cabinet members are going to spend time together, and bring suggestions to me during the next week. Thank you for your attention to this matter!”

An Intel spokesperson confirmed the meeting.

“Earlier today, Mr. Tan had the honor of meeting with President Trump for a candid and constructive discussion on Intel’s commitment to strengthening U.S. technology and manufacturing leadership,” the spokesperson wrote in an email.

Tan has been an Intel director since 2022, and in March he replaced Pat Gelsinger as CEO. Last week Sen. Tom Cotton, R-Ark., questioned Tan’s ties to China. Cotton brought up a past criminal case involving Cadence Design, where Tan had been CEO, and asked whether Intel required Tan to divest from positions in chipmakers linked to the Chinese Communist Party, the People’s Liberation Army and any other concerning entities in China.

Trump’s latest message marks a stark change in tone from last week. In a Truth Social post on Thursday, the president wrote that Tan “is highly CONFLICTED and must resign, immediately. There is no other solution to this problem.”

Intel said in a comment later that day that the company, directors and Tan are “deeply committed to advancing U.S. national and economic security interests.”

The Trump administration has taken a heavy hand in the business world, particularly in the semiconductor market, as the U.S. battles with China for supremacy in artificial intelligence. Over the weekend, Nvidia agreed to pay the federal government a 15% cut in return for receiving export control licenses that will allow it to once again sell its H20 chip to China and Chinese companies. Nvidia CEO Jensen Huang visited Trump in the White House on Friday.

President Trump on Monday said that he initially asked Nvidia for a 20% cut of the chipmaker’s sales to China, but the number came down to 15% after Huang negotiated with him.

“I said, ‘listen, I want 20% if I’m going to approve this for you, for the country,'” Trump said at a news conference in Washington, D.C.

Tan, 65, took over Intel after the struggling chipmaker had failed to gain significant traction in the AI market, which Nvidia dominates, while it was burning cash to build its foundry business for chip manufacturing.

Tan was born in Malaysia and raised in Singapore before moving to the U.S. and receiving a master’s degree from the Massachusetts Institute of Technology. He said in late July that his first few months as Intel’s CEO had not been easy, with layoffs and cuts to the foundry division.

Intel canceled plans for manufacturing sites in Germany and Poland and would slow down development in Ohio, he told employees.

“Turning the company around will take time and require patience,” Tan said on a conference call with analysts in July. “We have a lot to fix in order to move the company forward.”

Intel shares are up 3% this year as of Monday’s close. The S&P 500 is up 8.4%.

— CNBC’s Fred Imbert contributed to this report.

WATCH: President Trump demands Intel CEO resign

StubHub, the ticketing marketplace that spun out of eBay in 2020, has resumed its plans to go public and is now aiming to hold its IPO next month, CNBC has learned.

The company originally paused its IPO plans in April as the stock market was reeling from President Donald Trump’s “liberation day” tariffs. The decision came after StubHub submitted its prospectus in March indicating it would list on the New York Stock Exchange under the ticker “STUB.”

StubHub now expects to kick off its IPO roadshow after Labor Day, Sept. 1, and make its debut later in the month, according to a source familiar with the matter who asked not to be named because the discussions are confidential.

The company didn’t immediately respond to a request for comment.

StubHub also filed an updated IPO prospectus on Monday. It reported revenue growth in the first quarter of 10% from a year earlier to $397.6 million. Operating income came in at $26.8 million for the period, after the company lost $883,000 in the year-ago period, but its net loss widened to $35.9 million from $29.7 million a year ago.

The IPO market has come to life in recent months after an extended dry spell due to high inflation and rising interest rates. A flurry of startups have made their public debuts, including rocket maker Firefly Aerospace, design software company Figma, crypto firm Circle and AI infrastructure provider CoreWeave. Bullish, the cryptocurrency exchange that counts Peter Thiel as an investor, also filed its IPO prospectus last month.

StubHub has been a longtime player in the ticketing industry since its launch in 2000. It was purchased by eBay for $310 million in 2007, but was reacquired by its co-founder Eric Baker in 2020 for $4 billion through his new company Viagogo.

The company had sought a $16.5 billion valuation before it began the IPO process, CNBC previously reported. StubHub didn’t provide an expected pricing range for its shares in the filing.

As it prepares to go public, StubHub is contending with hefty competition in the online ticketing market. In addition to Ticketmaster, which is owned by Live Nation, StubHub is up against secondary market companies, including Vivid Seats, SeatGeek and TicketNetwork

For the first quarter, StubHub reported gross merchandise sales of $2.08 billion, up 15% from a year prior. That was a slowdown from 47% expansion the previous quarter. StubHub said GMS, or the total value paid by buyers for tickets and fulfillment, builds in each quarter and that initial sales for major concert tours typically occur near the end of the year.

WATCH: Recent first-day pops are for pre-AI companies