SpaceX's October 2026 acquisition of low-band 800 MHz spectrum for roughly $8 billion to build a competing terrestrial-satellite mobile network has reinforced trader skepticism toward any T-Mobile merger or acquisition announcement this year. The move positions Starlink Mobile as a direct rival to T-Mobile, Verizon, and AT&T, triggering sharp stock declines among carriers and prompting T-Mobile's CTO to emphasize the billions more required for full network infrastructure beyond spectrum holdings. With T-Mobile maintaining a limited satellite partnership while SpaceX advances independent FCC approvals for 15,000 Gen2 satellites, the competitive landscape and limited time remaining in 2026 underpin the 95% implied probability against a deal. A sudden regulatory reversal or major strategic pivot could still alter the outlook.