• Tesla bull Ron Baron said he thinks Elon Musk's $3 billion stake in Twitter isn't important.
• "It's a tiny investment," he told CNBC. "$3 billion for a man who is worth $300 billion. He has Tesla which is worth a trillion [and] on the way to being worth $3 or $4 trillion."
• Baron said his firm decided not to invest in Jack Dorsey's social media platform when it found out Musk was backing the company and taking a seat on the board.

Ron Baron, CEO of Baron Capital and one of Tesla's largest shareholders, said Elon Musk's 9.2% stake in Twitter, and his accompanying board seat, is not significant.

"I think it's meaningless," he told CNBC's "Squawk Box" on Thursday. "It's a tiny investment. $3 billion for a man who is worth $300 billion. He has Tesla which is worth a trillion [and] on the way to being worth $3 or $4 trillion."

Baron, who has been a Tesla investor since 2014, added, "There's no way this could be anything meaningful to him."

Baron said his firm decided not to invest in Jack Dorsey's social media platform when it found out Musk was backing the company and taking a seat on the board. Indeed, most investors tend to look at a company as well as the individuals who are backing it before they buy shares.

While Twitter's stock surged 27% after Musk's investment was disclosed Monday, the company's share price hasn't performed particularly well over the last few years compared with other U.S. tech giants like Apple and Microsoft.

Musk's purchase comes less than two weeks after he criticized the company, polling people on Twitter about whether it adheres to free speech principles. "Given that Twitter serves as the de facto public town square, failing to adhere to free speech principles fundamentally undermines democracy," Musk tweeted. "What should be done?"

Late last month, Musk also said he was considering building a new social media platform.

Musk, who is now Twitter's largest shareholder, isn't the only billionaire to snap up a hefty stake in a large media company.

Amazon founder Jeff Bezos came under scrutiny after he bought The Washington Post newspaper for $250 million in 2013.

After learning that Post reporters were looking into his past, former President Donald Trump railed against Bezos in a tweetstorm. Amazon shares fell while the broader markets rallied to record highs.

Asked if Musk's companies could now face similar scrutiny, Baron said, "When you're focusing on something that's meaningless and will never have any impact on anything, it just takes away from looking at the big picture."

He added: "These things, we don't care about. It's not relevant to me. People can pick up something. A short seller or long guy or a hedge fund is going to pick up something that you can trade on. It's not relevant. I don't care."

Elon Musk wasn't immediately available to comment.