Web news often trails the move it reports: a multi-agent trading system aligns news judgments with event windows and finds a weekly rank correlation of 0.119
A trading system for large language models reading Web financial news treats each news item as a testable unit and checks what its judgments mean against announcement-window abnormal returns and issuers' 8-K filings. The confirmatory reader emu's item judgments reach a weekly Spearman correlation of 0.119 (95% CI [0.098, 0.140]) with announcement-window abnormal returns, and event types agree with 8-K filings at AUC 0.833; measured from the first trade after publication, the correlation falls to 0.023, indicating that Web news often reports a price move already realized.