Shares of AT&T, Verizon, and T-Mobile fell more than 7% after Elon Musk's SpaceX announced plans to transform Starlink into a major U.S. mobile carrier. The announcement triggered a sharp sell-off across the traditional telecommunications sector as investors weighed the potential competitive threat from satellite-based mobile services. The simultaneous decline in all three major U.S. wireless carriers highlights market concerns about Starlink's potential to disrupt the established mobile landscape. SpaceX has been expanding Starlink's direct-to-cell capabilities, positioning the satellite network as an alternative to traditional terrestrial mobile infrastructure.