Space Exploration Technologies Corp (SPCX  ) announced a deal to acquire low-band spectrum from Grain Management Thursday. News of the deal has stocks of U.S. mobile carriers trading lower as SpaceX could become a major competitor moving forward.

The Spectrum Deal

SpaceX is acquiring the nationwide 800 MHz spectrum portfolio from Grain Management for an undisclosed amount.

"We announced an agreement to acquire a nationwide low-band spectrum license portfolio that will pave the way for Starlink to become a major mobile carrier in the US. With this new spectrum and our Gen2 constellation, Starlink Mobile can ensure Americans have access to high-speed mobile broadband no matter where they are," SpaceX tweeted.

In a blog post, SpaceX said the acquisition addressed a key technical gap for Starlink Mobile to become a major U.S. mobile carrier.

SpaceX said when it receives final FCC approval, Starlink Mobile will deploy and connect devices everywhere.

The company highlighted that the new low-band spectrum will help Starlink Mobile signal penetrate walls and other obstacles.

"Starlink Mobile can now become the first network operator to deploy both satellite and terrestrial spectrum. One network that provides Americans with a reliable service indoors, outdoors, in cellular dead zones, and everywhere between."

SpaceX CEO Elon Musk shared the news on social media and said this is a "very big deal."

Telecommunications Stocks Fall

SpaceX stock is up 2.56% to $164.68 in after-hours trading Thursday.

Shares of mobile carrier companies falling after hours significantly are:

AT&T (T  ): -7.92%

Verizon Communications (VZ  ): -6.90%

T-Mobile US (TMUS  ): -6.78%