OpenAI holds the strongest market-implied odds at 60% for finishing second on Code Arena’s WebDev leaderboard by year-end, driven by GPT-6 Astra Max’s consistent second-place scores near 1792 points behind Anthropic’s leading Claude Opus 5.5 Max. Recent September releases and iterative updates from OpenAI have narrowed gaps on agentic web-development tasks, while Anthropic’s mid-tier Sonnet 5.5 surge to third place signals intensifying competition among frontier labs. Chinese contenders like ByteDance and Z.ai trail at lower probabilities due to narrower margins on fullstack benchmarks. Traders are watching December model drops and vote-volume spikes for shifts, as the community-driven Elo-style rankings remain sensitive to new agentic capabilities and pricing adjustments.