Social media stocks are not in a bubble, billionaire investor Mark Cuban told CNBC on Friday.
The Dallas Mavericks owner, who made his fortune as an Internet entrepreneur, said in a "Squawk Box" interview: "It's not 1999 all over again by a long shot."
He disagreed with a report from the Federal Reserve, stating valuations are stretched for smaller social media and biotech stocks. Fed chair Janet Yellen went so far as to pledge last week on Capitol Hill to remain vigilant over asset possible bubbles.
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Cuban may not be seeing bubbles, but he said the fact that Twitter and Netflix have similar stock market valuations is crazy.
"I think Twitter has its challenges. It'll improve its monetization like Facebook did. Facebook has its challenges," said the "Shark Tank" co-host. But I think Netflix is game-changing and has an opportunity to really change the game to present content even more."
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On the Supreme Court decision against online TV service Aereo, Cuban said he wasn't surprised that upstart company lost.
Last month, the justices ruled that Aereo—backed by media mogul Barry Diller—violated copyright law by using tiny antennas to provide subscribers with broadcast network content via the Internet. It was a victory to the major TV broadcasters, including NBC. (Comcast owns NBCUniversal, parent company of CNBC.)
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Cuban had tried to do the same thing as Aereo in the late 1990s—provide broadcast television over the Internet through his broadcast.com website.
"We tried it way back when," he said. "It's an idea that makes sense but not an idea that we thought would legally pass then ... or pass now."
"It was a good try. But it didn't surprise me that [Aereo] didn't work," he said.
—By CNBC's Matthew J. Belvedere