Telecommunications stocks sold off on Friday after Elon Musk‘s SpaceX announced an agreement to purchase a nationwide spectrum portfolio, aiming to expand its Starlink internet into mobile service.

Verizon was down roughly 7% on the news, and is pacing its worst day since 2002. Shares of T-Mobile were down 12% while AT&T fell around 10%. SpaceX stock climbed slightly, around 1% for the day.

The deal includes acquiring the spectrum from Grain Management, which SpaceX described as a “license portfolio of up to 14 megahertz of paired spectrum in the 800 MHz band,” in a Thursday statement.

FCC Chair Brendan Carr, whose agency will oversee approval of the deal, said that competition in the spectrum market was “really good news for the American consumers” in a CNBC interview.

“We’re probably going to bring over $100 billion of spectrum into the market over the next two years, so we’re seeing a lot of competition,” Carr told CNBC’s “Squawk on the Street” on Friday.

“There’s going to be moves in the market. People are going to try to out-compete, out-innovate, and I think that’s great. We’re going to see how this plays out. It’s not for us ultimately to pick winners and losers,” he added.