Will Anthropic have the best AI model at the end of May 2026?

Prediction markets put the probability at 60%: Will Anthropic have the best AI model at the end of May 2026. Currently, markets are divided (60% YES, 40% NO). OpenAI announces GPT-5.5, its latest artificial intelligence model.

What’s Happening

The race to claim the title of the best AI model by the end of May 2026 has intensified following a flurry of major announcements and security incidents. On April 23, 2026, OpenAI launched GPT-5.5, which the company described as its "smartest and most intuitive to use model" yet, featuring significant improvements in coding, computer use, and scientific research capabilities [CNBC, Apr 23]. This release came less than two months after GPT-5.4, underscoring the breakneck pace of development in the sector. However, the launch was immediately contextualized by a major controversy surrounding Anthropic's rival model, Mythos, which a former national cyber director warned can "hack nearly anything" and poses unprecedented risks to critical infrastructure [Fortune, Apr 23]. These competing narratives have placed the question of whether Anthropic have the best AI model at the end of May at the center of industry debate.

The security breach at Anthropic has become a pivotal factor in the competitive landscape. On April 22, 2026, a group of unauthorized users reportedly gained access to Mythos, an AI model that Anthropic had deemed "too dangerous to release" publicly due to its ability to discover flaws in virtually any operating system or software [Euronews, Apr 22]. The incident has raised serious questions about Anthropic's deployment and security protocols, even as the company investigates the breach. Meanwhile, OpenAI has positioned GPT-5.5 as a direct competitor, with technical staff member Mia Glaese stating that the model would have a significant impact on digital defense strategies [TechCrunch, Apr 23]. The timing of these events has created a volatile environment where the definition of "best" — whether measured by raw capability, safety, or real-world utility — remains contested.

Looking ahead to the end of May 2026, the outcome hinges on how both companies navigate their current challenges and opportunities. Anthropic must address the security fallout from the Mythos breach while potentially accelerating its release timeline to counter OpenAI's momentum. OpenAI, for its part, is leveraging GPT-5.5's immediate availability to ChatGPT Plus, Pro, and Business users to capture market share and benchmark leadership [MLQ.ai, Apr 24]. The broader industry is watching to see if Anthropic can recover its reputation for safety-first innovation or if OpenAI's aggressive iteration cycle will solidify its position. The question of whether Anthropic have the best AI model at the end of May will ultimately be decided by independent benchmarks, user adoption rates, and the resolution of the security incident that has cast a shadow over the company's flagship product.

Traded on Polymarket — $73K Volume

Lower-volume market on Polymarket ($73K). Wider spreads expected — enter with limit orders and be aware of slippage risk. Currently 60c YES.