BIG Fiber (bigfiber.com), a provider of purpose-built underground dark fiber networks, has raised $250 million in debt financing led by Stonepeak Credit and La Caisse. The company designs 100% underground, high-capacity, low-latency networks for mission-critical data centers, hyperscalers, and enterprises across the San Francisco Bay Area, Greater Portland, and Greater Atlanta. The capital will support network expansion and refinancing.
AI Data Centers Fuel Dark Fiber Demand
The financing arrives as AI infrastructure expansion accelerates demand for dedicated metro dark fiber interconnects. BIG Fiber's approach focuses on newly constructed underground routes optimized for low latency and high capacity, contrasting with legacy providers' patchwork networks.
Legacy Infrastructure Limits AI Workloads
Traditional fiber networks, often aerial or decades old, face congestion and limited scalability for AI traffic patterns. Hyperscale data centers now require extreme route diversity and dense connectivity that older systems struggle to deliver at scale.
Underground Construction Delivers Differentiation
BIG Fiber builds 100% buried networks with high fiber counts from day one, targeting underserved corridors in key AI markets. This avoids overlaps with mature operators while providing physical security and future-proof capacity.
"We’re seeing customers require extreme route diversity… making purpose-built metro fiber essential." - Patton Lochridge, CCO
Infrastructure Specialists Back Expansion
Stonepeak Credit, an $88 billion AUM firm focused on digital infrastructure, and La Caisse led the facility, which includes a $100 million accordion feature. Their involvement signals conviction in dark fiber as critical AI-era connectivity assets with predictable cash flows.
Dark Fiber Market Expands Rapidly
The dark fiber network market stood at $6.90 billion in 2025 and is projected to reach $21.88 billion by 2033, growing at a 15.9% CAGR. per Grand View Research. Capital flows toward operators building new capacity in power-rich regions amid AI-driven interconnect needs.
Experienced Team Drives Execution
Leadership brings deep domain expertise from Zayo, AGL Networks, and Level 3, supporting aggressive buildouts including the recent San Jose Ring completion and 65+ on-net data centers in the Bay Area.
Network Milestones Signal Momentum
Recent activity includes multiple data center on-net announcements and hiring of senior sales talent in Atlanta and the Bay Area. The company continues expanding route miles across its three core markets.