BT's market value plummeted by over £1 billion after Sky announced a partnership with CityFibre to deliver broadband services, marking a significant shift in the competitive landscape of the UK's broadband market. Sky, which currently relies on BT's Openreach for its broadband services, will begin using CityFibre's network from 2025, raising concerns among BT investors about potential price pressures and increased competition. As a result, BT's share price fell by more than 8%, erasing gains made following an investment by Bharti Enterprises. Analysts suggest that while the move poses challenges for BT, the long-term impact may be manageable, as Sky will continue its relationship with Openreach. CityFibre, aiming to expand its coverage from 3.8 million to 8 million premises, is expected to focus on rural areas where BT's infrastructure is less developed. The intensifying competition may lead to further consolidation among alternative networks, posing additional threats to BT's market dominance.