Elon Musk Teases Grok 4.20 Release in 3-4 Weeks
Elon Musk posted on X that xAI’s Grok 4.20 will release in 3 or 4 weeks. The post came on December 7, 2025. That puts the launch around late December 2025 or early January 2026. Gadgets 360, Dataconomy, Gizbot, India TV, and PANews reported the announcement.
Stealth Test on Alpha Arena
Users spotted Grok 4.20 in stealth mode on Alpha Arena before the announcement. The platform runs AI models through stock-trading simulations with $10,000 starting capital and real-world stock prices. In season 1.5, ending December 3, 2025, it beat rivals. NextBigFuture details how the model, called a “mystery model” at first, hit 12.11% return on average across instances—one of four strategies peaked at 47%.
- Dataconomy and India TV report 12% profit for Grok 4.20.
- GPT-5.1 lost 9.47%, Gemini 3 Pro lost 32.82%, Claude Sonnet 4.5 lost 40.91%.
- It traded U.S. stocks like TSLA and NVDA autonomously, using up to 20x leverage on Hyperliquid perpetuals.
Musk confirmed it was Grok 4.20 on X, per NextBigFuture.
Quick Follow-Up to Grok 4.1
Grok 4.1 launched in November 2025. This makes Grok 4.20’s cycle about a month, showing xAI’s fast pace. Separately, Grok 4.1 Fast set an OpenRouter record last week: 1.16 trillion tokens processed, beating Claude 4.5 Sonnet, Opus, and Gemini 3 Pro. Dataconomy and India TV note this as a sign of developer demand, though it’s just one platform’s metric.
xAI hasn’t shared more specs yet. Check Alpha Arena at nof1.ai for live trade logs.
