SpaceX is moving to become a real phone carrier, which is bad news for Verizon, AT&T and T-Mobile and potentially good news for anyone tired of high phone bills.

• SpaceX is buying low-band spectrum, the type of signal that can get through walls, so Starlink phone service can finally work indoors.
• Starlink beams signal down to towers, and low-band then spreads it into homes and buildings — the main complaint about satellite phone service.
• The big three carriers keep prices high by selling the same network cheap under side brands like Mint Mobile instead of cutting their headline plans.
• T-Mobile and Apple have both partnered with SpaceX, which looks like an attempt to stay close to the threat rather than fight it.
• SpaceX stock fell about a third after its IPO, but the business looks stronger now, with support seen around the low $130s.

Outlook: Expect SpaceX to push harder into consumer phone service, squeezing the carriers' pricing power over the next few years.