A fund manager of a FANG-focused ETF thinks Facebook Inc. is destined to turn into MySpace.

“Any social media platform, in time, is going to become MySpace,” said Sabretooth Advisors chief investment officer Scott Freeze, who manages the New Tech and Media ETF US:FNG. “Nobody young uses Facebook.”

“ Any social media platform, in time, is going to become MySpace. Nobody young uses Facebook. ” — Scott Freeze, chief investment officer at Sabretooth Advisors

Freeze said the latest debacle involving Cambridge Analytica’s access to user data “quickens the demise,” as people are going to be less inclined to use Facebook’s FB, -1.73% service in the wake of the latest controversy. He doubts that Facebook will be able to monetize its Instagram property, which has escaped much of the backlash, in the same way that the company monetizes the core Facebook platform.

“It’s a great service, a great idea, but you’ve got a lot of people letting their political views interfere,” he told MarketWatch.

A key concern for Facebook investors, according to Freeze, is the E.U.’s plan to make users opt-in to sharing certain information, rather than opt out. “Nobody” is going to actively opt in, he said, which could “really handcuff what they do advertiser-wise.” He added that he wouldn’t be surprised if the U.S. government moved toward a similar policy over time as it continues to scrutinize data-privacy and other issues.

Should antitrust laws be enforced against the tech giants' monopolies?

Freeze no longer considers Facebook to be behaving like he imagines a FANG stock should—he feels the same way about Google-parent Alphabet Inc. GOOGL, -1.44% , for that matter—and thinks that rapidly expanding Square Inc. SQ, +4.21% is a better bet, even with its shares up 246% in the past year. Square has “more upside potential than Facebook does,” according to Freeze.