MARA posts $1.7B Q4 loss on bitcoin markdown; stock up 15% after Starwood AI JV

MARA Holdings reported a fourth-quarter net loss of $1.7 billion, driven by a $1.5 billion fair-value hit as bitcoin fell around 30%, while revenue declined 6% to $202.3 million. The company also announced a joint venture with Starwood Capital Group to build AI-focused data centers, and its shares rose more than 15% on Thursday.