Recent endorsements of Dario Amodei’s September 2026 “We Must Pace the Frontier” essay by OpenAI, Google DeepMind, and xAI leaders, alongside ongoing working-group talks among Anthropic, OpenAI, and Google since July, have fueled some trader optimism for coordination. However, the late-September White House Accord—signed by those labs plus Meta, Nvidia, and xAI—remains strictly voluntary, focused on internal controls and external evaluators rather than any explicit joint limit on capability advancement. Antitrust constraints, competitive pressures, and the absence of a formal lab-led agreement or government waiver continue to limit the likelihood of a binding pacing pact before year-end, supporting the current 68.5% market-implied probability of no announcement.