The "Up-Only" narrative of 2025 hit a brutal wall in the final quarter, as the U.S. crypto exchange, Coinbase, reported a staggering $667 million net loss for Q4. The sudden plummet of Bitcoin from its $120,000+ peak to sub-$90,000 levels triggered a liquidity vacuum and massive book losses. While Coinbase remains anchored by its $11.3 billion cash pile, the results signal a systemic stress test for the entire industry.