An extensive analysis of Anthropic’s approximately 259,000-word corporate prospectus using the AI detection tool Pangram has yielded unexpected results, indicating that the vast majority of the document was likely authored by humans. According to the findings, about 92% of the filing was judged to be human-written, although specific sentences and paragraphs were marked with high confidence as containing traces of artificial intelligence use.
Because the document’s sheer size posed technical challenges for standard testing methods, Business Insider reporters enlisted the help of Pangram co-founder and Chief Executive Officer Max Spero to complete the full-text evaluation. Spero interpreted the results to mean that while the document may have undergone light AI editing or minor sentence-level polishing, there was no indication that large portions of the text were entirely generated by machine learning models. Sentences flagged by the tool as potentially involving AI assistance included a passage discussing the rapid pace of industry development, noting that new model iterations arrive on monthly rather than yearly cycles.
Industry observers and tool developers alike emphasize that AI writing detectors are not infallible. The nuances of human editing, proofreading, and incorporating AI-suggested phrasing adjustments can influence detection outcomes. In a previous test, a journalist who ran personal writing samples through Pangram found that a single sentence was flagged as AI-generated after the author had accepted a rewriting suggestion from ChatGPT.
Anthropic did not respond to requests for comment regarding the detection results. Furthermore, the company’s proprietary AI watermarking system has not yet been made available to the general public, meaning it was not utilized for this assessment.
The findings raise questions about corporate transparency and technology adoption within the artificial intelligence sector, particularly why a leading AI firm did not rely more heavily on its own Claude assistant for drafting a major regulatory filing. However, legal and financial analysts note that prospectuses submitted to the U.S. Securities and Exchange Commission undergo intense scrutiny, where every single sentence is subject to rigorous legal review, making heavy human oversight and authorship a standard precaution.
