The UK's Competition and Markets Authority (CMA) is investigating Amazon's $4 billion investment in the AI startup Anthropic, concerned that the partnership may affect market competition in the UK. The investigation is based on information gathered by the CMA, which believes the collaboration could have adverse effects. Amazon has expressed dissatisfaction, stating that the partnership meets market standards. The CMA has collected public opinions and plans to assess the impact of the partnership on the market in the coming weeks, with a final decision to be announced on October 4. The investigation involves Anthropic's use of Amazon Web Services.