Bernstein lowered its price targets for Verizon, T-Mobile, Comcast and Charter Communications, citing the growing competitive threat from SpaceX’s Starlink. The firm said SpaceX’s planned entry into the U.S. mobile carrier market will fuel a prolonged debate among investors about its potential impact.

The analyst action followed SpaceX’s announcement that it is acquiring low-band spectrum to expand Starlink into a major U.S. mobile carrier. Bernstein maintained its Market Perform rating on the stocks, but said SpaceX’s potential competition and recent pricing moves by incumbent carriers add pressure and uncertainty to an already mature market.