Meta's Muse Spark Sends Stock Up 9% — Goodbye, Llama?

Meta just shipped Muse Spark, the debut model from its Meta Superintelligence Lab (MSL) — and it's a hard pivot from the open-source Llama era. Unlike Llama, Spark is closed, natively multimodal, and built from scratch to reason across text, image, video, and audio in a unified framework.

The model runs 10x leaner than Llama 4 Maverick while offering Instant, Thinking, and an upcoming Contemplating mode — the last one spins up parallel subagents for complex tasks, going head-to-head with GPT-5 and Gemini Deep Think. It scored 42.8 on HealthBench Hard, claiming a wide lead over rivals after Meta worked with 1,000+ physicians on health tuning.

Markets noticed: META stock jumped ~9% on the news. Alexandr Wang's $14B hire is paying off optics-wise, at least. Spark rolls out in Meta AI app first, then Facebook, Instagram, WhatsApp, and smart glasses.

Why it matters: Meta is making a serious closed-model bet for the first time — if Spark delivers on benchmarks in the wild, the AI race just got a new credible contender.